US2553062A - Fluid fuel combustion apparatus and control therefor - Google Patents

Description

May 15, 1951 Filed Oct. 5, 1945 W. L. RIEHL FLUID FUEL comsus'rzou APPARATUS AND CONTROL THEREFOR 2 Sheets-Sheet 1 May 15, 1951 w. L. RIEHL 2,553,062

FLUID FUEL COMBUSTION APPARATUS AND CONTROL VTHEREFOR Filed Oct. 5, 1945 I 2 Sh ets-Sheet 2 Fig. 4

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gi @daw/VQM i atented May 15, 195i William L. Riehl,;Marey, N. Y assignor to Union Fork & H e Company, Columbus, Ohio, a corporation of Ohio Application was 1945, sea-1" o; 6203514 This invention relates to combustion apparatus and" is particularly useful for such apparatus when supplied with'fluid' fuel.

An object of the invention is to provide an 1m proved combustion" apparatus which will insure efficient combustion of fuel.

Another object is to. provide an improved combustion apparatus which will be composed'of few and simple parts.

Another object is to provide an improved combustionapparatus which: may be easily and economically manufactured.

Another object is to provide animproved com"- bustion apparatus'which will control combustion accurately in accordance with heat requirements.

Another object 'is'to provide an improved'com-- bustion apparatus which will be extremely safe.

Another object'is'to provide an iinprovedcornbustion apparatus which'will be fully automatic in its operation.-

Another object is to providean improved com bustion apparatus which will effect its control through a single valve.

Other objects will hereinafter appear.

Thejnvention will be better understoodfro'm the description of two practical embodiments thereof, illustrated in the accompanying drawings, in which;

Figure 1 is a somewhat fragmentary sectional view of a control apparatus designed'ior the handling of gaseous fuel and for burning this fuel under sub-atmospheric pressures, electrical circuits being shown diagrammatically; and parts of the apparatus broken away;

Figure 2 i a diagrammatic representation "of" certain parts of the apparatus of'Figure 1 showing their control circuits; Figure 3 is a wiring diagram similar to Figure"2,

but showing control circuits as they maybe ar ranged when a plurality of units are usedtogeth'er connected to a single source of sub-atmospheric pressure or for one or more units arranged for" combustion above atmospheric pressure;

Figure 4 is aview similar to Figure 1 showing a modified form of apparatus arranged'for burning fuel at pressures above atmospheric;

Figure dis a fragmentaryelevational View of a" modified form ofthermostat mechanism'similar" to that shown in Figures 1 and 4;

Figure 6 is a transverse sectional view taken on" the line VI-VI of Figure 5; and

bustion chamber is shown at lfthis being'proseams. (c1. is's' -iiuf vided with a removable bottom or plate 2 secured to the chamber as by screws 3, which furnishes meansof access by which the burner 4 may he 4 inserted or removed from the combustion chamber.

A conduit 5 leads from the combustion chamber to ameans'. for. reducing the pressure within-the" combustion chamber and withdrawing gases:

therefrom, shown as a blower or pump Bdriv'en 10 by an electric. motor I.

Gas or other combustible through a conduitor pipe 8 to acontrolapparatus which regulates its passage to the burner U drawn through these ports by the vacuum Sexist-a ing in thezcombustionichambervat a rate which.

will maintaincombustion suflicient to take care of the heat requirements to be met by the apparatus.

Connectedjto the ofjconduitlaiis a 9, one branch. of whichiis connected vby a. short piece'of p'ipe ornipple ll! ,toayalve bodylla the capbeing threaded to the branch or the body;

PH Q Q. tha c n e ed to the n pple .l 6, and: provided with alock nut 2 [,sothat valve l8may be adjusted toward orirorn the end of pipple 16,, by means'of its threaded shank and may be,

clamped in'any adjusted position by the lock nut."

Theoutletbraneh 'cf valve'bodyfll fi t iiii taif fli lg mra -h fi t 3 he. lateralbranch'of which is connected to apiece of pipe 24 carrying at its end a valve .or stopcock 25 'bywhi ch' air may be admitted and its admission regulated;

The remaining barrehtr aagzs is @nhaaf byme aiis of a tube 26 'to'the bottom of the bumi'i'al A q H, rro m fi- 9, a street elbow 2 l connects with electrically controlled valvefllZS and from valve a tube 29 extends to the outer sleeve iw of fluid is supplied connected by ai.

3 a pilot burner, thus bypassing fuel around valve l3;

In the interior of this burner is secured a cylindrical ceramic holder 31, substantially concentric with sleeve 30, which carries a coil of resistance wire 32, the sleeve and holder being spaced apart throughout their peripheries and the wire being so positioned that a film of gas may pass up through the annular space between the sleeve 35 and central holder 3|, issuingv exterior of holder 3|, or may be separate there from, as a ring of corrugated sheet metal.

Depending from the valve I3 is a stem 33 which 4 pansible material, and stainless steel is found to be very satisfactory for this part.

The bottom of the tube is threaded into the top of a housing as secured to plate 2, and the housing carries'two switches 55 and 55 which may be adjusted toward and from the depending arm or lever 52 by means of set screws 57.

The upper perforated part of tube 50 is, of course, in very close proximity to the flame of the pilot burner which emanates from the top of tube 35, so that the side of the tube 55 closest adjacent this flame will, while the flame is burning, be heated to a higher temperature than the side remote therefrom, and the differential expansion of the twosides of the tube cause it when heated to bend slightly to the right as seen in Figure 1, movingthe lower end of lever arm 52 to extends through a somewhat larger perforation in the boss l5 into the space within a casing secured to this boss, 'the casing consisting of an upper part or top 34 and a lower part or bottom 35, these parts being secured together by means The upward movement of the valve stem 33 which permits the closing of switch 42 before valve [3 opens, is permitted by the clearance provided by the slidable telescopic arrangement of the upper end of valve stem 33 and its reception in the recess of the depending hub of valve [3.

Thus, it will be seen that the space between the diaphragm 3'! and upper housing section 34 is subjected to the reduced pressure which exists in the. discharge side of the valve body H and that the bottom of the diaphragm is exposed to atmospheric pressure entering through the perforation around valve stem end 39.

Consequently, a differential pressure tending to move the diaphragm up exists only when a subatmospheric pressure is present in the combustion chamber, from which it is transmitted to the discharge side of valve l3.

- Above valve l3 and directly in alignment therewith is a disc or plunger 45 carried by rod 46,

the disc being pressed toward the valve by a spring 47, and capable of being retracted therefrom by an electric motor 48 contained within a housing 49, threaded on boss I4 of valve body II.

The tension of spring 4'! must, of course, be sufficient to overcome the valve-opening force of diaphragm 3i, and the motor 48 must have enough power to retract the plunger 45 against the pressure of the spring, so that the plunger 45 through the tube. The tube may be of any ex-;

the left, and thus opening switch 55 and closing switch 56. The motion of the tube top is magnified by lever 52 which is substantially longer than the tube, as shown..

In the absence of flame from either the pilot or main burner, tube again resumes its vertical position, opening switch 55 and closing switch 55.

Current is supplied to motor I by conductors 58 and 59, the current coming from power lines 53 and 5!, the former of which is connected directlyto line 59 and the latter of which is connected through an electro-magnetically controlled switch 52 to conductor 58.

Arranged in parallel with switch 52 is the primary 33 of a transformer, the secondary 5d of which is connected by conductor 55 to the coil 36 which actuates switch 52, this coil being connected in turn by conductor 55 to a room thermostat 58, theopposite side of which is connected to secondary 64.

Thus, it will be seen that whenever heat is required, the contacts of thermostat 58 close, completing the circuit through secondary 6d and coil 55, closing the circuit to motor I, while as soon as the temperature has risen sufiiciently to open the contacts of thermostat 58, switch 32 is opened,

discontinuing the supply of current tomotor I. Figure 2 shows the circuits controlling the supply of fuel, these circuits being supplied by current from the main power line through a plug 55 and conductors 55 which convey this current to the primary H of another transformer.

From the transformer secondary '52 extend conductors 73 and M. In conductor '54 is interposed switch 42, and this conductor terminates at the switches 55 and 55. Connected to conductor '13 and to conductor 14 between switch 42 and "switches 55 and 55 is the coil of valve 23, while valve motor 43 is connected between conductor 73 to switch 55. v I

Conductor i3 terminates at the ignition coil 32, from which a conductor 35 extends to switch 55.

The operation of the device described is as follows:

Until there is.a demand for heat, thermostat 68 remains open and the motor l cannot operate. In this condition, there is atmospheric pressure in the combustion chamber and above diaphragm 31, so that the diaphragm remains in its lowermost position (as shown in Figure l), holding switch 42 open and preventing any current from passing through the circuits of Figure 2.

Of course, the valve I3 is closed upon its seat l2, and the spring 51 presses the disc :35 tightly down upon it to hold it .there. Consequently, no

gas can pass through the main line to the burner.

Similarly, valve 28 is closed, as no current is ZJQQiQQQ housing 34 above diaphragm 3'1. 1Q

This reduction in pressure above the diaphragm permits the atmospheric air pressing uponits lower surface to raise the diaphragm slightly until the end of valve stem 33, contacts valve I3, which allows switch 42 to close.

Current now may travel through the coil of switch 28 and switch 42, causing the valve. at23 to open and admit a pilot supply of g as to the. e 30,

At this stage, thermostat tube 501s cool, hence switch 55 is closed andswitch 56 is open,

Current, therefore, cannot pass through motor 48, but does passthrough ignition coil 32, con: ductor [5, switch 55, back to conductor 14, causing the ignition coil to become incandescent and to ignite the gas which emerges from, tubeBG.

The pilot flame, heating thermostat tube 50, causes this to bend to the right, swinging the lower end of arm 52 to the left and thus opening switch 55 and closing switch 56. 30

The opening of the former switch breaksthe circuit through the ignition coil, while the closing of the latter completes the circuit through motor 48 which immediately retracts the stem IIiand disc 45 from valve I 3, permitting thisvalve to functionfreely. as the diaphragm 31 rises with. the increase of suction above it.

Thus, gasis admitted. not onlyto thepilot burner, but to the main burner, which latter .flow. is ignited by the flame ofthepilotburner, and. valve I3 is controlledby thesuction as longas these conditions obtain.

As soon, however, as the need for heat" has been met, the contacts of thermostat BB open, and motor I .isstQpped. Immediately the presu Within. the .combu'stionchamber rises and is transmitted to .theuppersideof diaphragm 31, causing'it to drop.and.to open switch 42;. break ing the circuits th'roughvalve 28.,and-motor 48, and thus .closing. boththepilot valve 28 and the main valve I3.

Assoon as theflame within the combustion chamber has burned out, thermostat 5!! moves to the left; again closing switch. 55.1 and opening switch 56, so that the parts. are readyrtofunction. .55 through their cycleagain upon the .next-actuae tion of thermostat 68.,

It willbe noted that no gas may be admitted through valve I3 or 28funless the properoperationofthe suction fanhas commencegl and that l' asmw P s a ve '3 un es aflameexists. at the pilot burner. Gas maybe admittedtojhq. pilot burner only when a proper vacuum exists and simultaneously with thesupply of current 7 to the ignition coil. 7

'The'valve I 3'being controlledby the diaphragm 31 which is' actuated'b'y' the pressure difierential betwee'n the atmosphere and the pressure in. the conduit beyond the valve acts as a regulat r of flow o'r'pressure in" that portionlof'ltheconduit 70 between it and the orifice valvelfi, so. that it is in'effect a combined pressure regulator 'and ma fuel valve. Its operation ion atmospheric pressur and acuum make "it also a .vaai umssray Syn The" speed with. which thejvalve react on I licen e dep nd nt. u on. t e ime nccessarr;.-te

exha st ases, irom. he sp ce. above. diaphra m. 3. 9 5.0. m rbedetermin d by the. amount Iot-= pac whic is eft-in he n n througnit-ne. boss l5 and around shank 33. If it. is -.desired to.

' i ure h v lveper t n slowly, Wi ho abrup jar, b s On n ssary. to restri t the o le lin about thestem 33, it only being, necessary that. there be suflicient space for gas to be drawn alonge. side the stem.

Figure. 3; is shown, a. modification, Ofdlihflfllm cuit of Figure 2, the only change being the. i113e1 tion of theroom thermostatl 68 inthe line I 13 -im.-.

mediately adjacent the secondary 1 2 of the-trans.

former.

This circuit is intended for use Where a. num-. ber of units suchasshownin Figure 1. are; con-.. nected to a common blower which is .operatect continuously,

In these circumstances, when the need for heat:

arises, thermostat I68 closes and completesthe circuits through the pilot controlavalve 2&, .-themotor 48 and the ignition coil 32 directly, instead of through creating the suction. The; switch 42-preventsany undesired supply of -gasi should the common, blower be outof, operation-,;

but otherwise the cycle of, operation is precisely, the same as that above. described.v

In Figure 4 is shown an arrangement ofv the, control of Figure 1 whichhasbeenv adapted to;

systems which are not operated belowv atmos pheric pressure.

The only structural changes in theapparatus are that the casing bottom has been replacedawith a casing bottom I35 which, instead... of :carrying a switch 42,; has, a depending; central-,- boss MI carrying a spring I42bearing. directly; on the lower diaphragm plate, from which pres-a. sure is transmitted to the headAE! atithe lower. end of the stem 33,, and theswitch 42 has been-'.

omitted. The gas pressure on the uppersure.

face of diaphragm 3! acts, against ,the.atmos-,,.

pheric pressure on the lower side of this vdia-. phragm, plus the pressure of spring I42, which, of course, is adjusted ,so that any excessive gas pressure will overcome theiorce of the spring.I The pressure in.v the conduit beyond valve I3 is somewhat above and permitthe valve to close,

atmospheric, as it must be suflicient to cause sufiia cient fuel to flow past the restricted portion of E the conduit, as in the case of the. first described;

Beyond this vsection the velocity of the gas, as well as the draft created by the stack, are sumcient to draw inadequate air to;

embodiment.

support combustion.

The diaphragm 3?, in this embodiment, serves; to control the opening of valve I3 from, its seatv I2 according to the pressure which existsin conlimiting the possible opening motion of valve l3 in accordancewith the supply of current to the motor, which current in turn is controlled by v room thermostat I 68.

The control circuit, in this instance is precise ly the same as that shown in Figure 3, with the omission of switch 42.

It will be seen that the main valve is maintained closed unless a flame exists toignite theiueL; and that the electric ignition. is controlled. as,

above described.

In Figure 5, a modification of the-thermos static device of the preceding figures is shown, in which the tubular element has been provided with two elongated diametrically spaced slots instead of the series of perforations 53 of the preceding figures.

In this form, the tubular element is shown at 250, it having a'closed upper end 25!, and two diagrammatically disposed elongatedaxially extending slots 253.

The central lever 252 is clamped within the closed end 25l, as in the first figure, but extends ,at its lower end into a fitting 254 in the form of a conventional pipe-T, where it is connected to a rod 255 extending laterally through the side branch of the T and through a fitting 256', to which is clamped a diaphragm'25'l by means of a ring 258, which seals the space about the rod 255. The end of the rod engages a switch 259, corresponding to switch 55 of the preceding figures.

The lower branch of the T is conveniently closed by a plug 260.

In Figure 7 the slots 353, are shown as penetrating nearly but not quite through the tubular element 350. The thin remaining portions of. the wall where defined by these slots or slot-like grooves are so small that heat is not readily conducted through them, and the action is precisely the same as that of the preceding modifications, excepting that with this form of the device, the interior of the tubular element is sealed from the sub-atmospheric pressure of the combustion chamber, and'the diaphragm 25'? or other sealing means may, therefore, be eliminated.

While I have described the illustrated embodiments of my invention in'some particularity, obviously many other embodiments, variations, and modifications will readily occur to those skilled in this art, and I do not, therefore, limit myself to the precise details shown and described herein, but claim as my invention all embodiments, modifications and variations coming Within the scope of the appended claims.

I claim:

1. In a combustion apparatus including a combustion chamber, power operated exhausting means connected therewith, a burner in said chamber and 'fuel conducting means connected therewith, a valve interposed in said fuel conducting means, pressure responsive operating means operatively associated with said valve controlled by the difference in pressure between that existing at the burner and that of the atmosphere and capable of opening and closing the same, closing and holding means operatively associated with said valve, resilient means Luging said closing and holding means into valve closing position, electrical retractin means capable of moving said closing and holding means from valve closing position, and control means for said closing andretracting means controlled by the presence or absence of a flame at said burner.

2. In a combustion apparatus including a combustion chamber, power operated exhausting means connected therewith, a burner in said chamber and fuel conducting means connected therewith, a valve interposed in said fuel consaid closing and holding means into valve'closing position, electrical retracting means capable of moving said closing and holding means from valve closin position, and control means for said closing and retracting means controlled by the presence or absence of a flame at said burner, said pressure responsive means having limited movement independent of said valve, and a control actuated by said pressure responsive means during said limited movement preventing release of said valve holdin means until the pressure responsive means has completed its limited movement.

3. In a combustion apparatus including a combustion chamber, power operated exhausting means connected therewith, a burner in said chamber and fuel'conducting means connected therewith, a valve'interposed in said fuel conducting means, pressure responsive operating means operatively associated with said valve and responsive to pressure'changes in the fuel conducting means between the valve and the burner, closing and holding means associated with said valve, including resilient means capable of closing the valve against the pressure responsive operating means and electrical means capable of moving said closing and holding means to position permitting the valve to open and controlled by the presence or absence of flame at said burner,said pressure responsive means having limited movementindependent of said valve, and a control actuated by said pressure responsive means during said limited movement preventing release of said valve holding means until the pressure responsive means has completed its limited movement, branch conduit means from the fuel conducting means on the side of the valve remote from the burner to a pilot burner adjacent said first mentioned burner, and a control valve in said branch conduit means controlled by the pres sure responsive means during its independent movement. a

4. In a combustion apparatus comprising a combustion chamber, a main burner therein, a source of fluid fuel under pressure, a conduit connecting said source of fuel with said'burner, a branch conduit from said first mentioned conduit, a pilot burner connected to said branch conduit and adjacent said main burner in said I combustion chamber, a source of suction connected to said combustion chamber, a valve in said main conduit between the branch conduit and the main burner, a pressure responsive element operatively associated with said valve and having limited movement with respect thereto when the valve is seated, a valve contacting element arranged to engage the valve and urge the same toward its seat, a, spring operatively associated with saidvalve contacting element and. capable of pressing the valve against its seat: and overcoming the pressure of the pressure re-- retracting; means connected to said valve contacting eleoperatively associated withsaid valve andca- V pable of moving it from its seat, a plunger in alignment with said valve, a compression spring urging the plunger against the valve, and electro-magnetic means arranged to retract the plunger against the pressure of the spring.

6. In a combustion controlling apparatus a valve comprising a body having a seat, a valve having a head movable into and out of engagement with said seat, a diaphragm operatively associated with said valve and capable of moving it from its seat, a plunger in alignment with said valve, a compression spring urging the plunger against the valve, and electro-magnetic means arranged to retract the plunger against the pressure of the spring.

7. In a combustion controlling apparatus a valve comprising a body having a seat, a valve having a head movable into and out of engagement with said seat, a diaphragm operatively associated with said valve and capable of moving it from its seat, a plunger in alignment with said valve, a compression spring urging the plunger against the valve, and electro-magnetic means arranged to retract the plunger against the pressure of the spring, the diaphragm being movable after the valve is seated; and means limiting the movement of said diaphragm.

8. In a combustion apparatus comprising a combustion chamber, a source of fluid fuel under pressure, a conduit from said source of fuel to said combustion chamber and terminating in a main burner, a branch conduit from said first mentioned conduit to said combustion chamber and terminating in a pilot burner, a valve in said conduit between the branch conduit and the main burner, pressure responsive means capable of opening said valve operatively associated therewith and having a limited movement independent of said valve, resilient valve holding means operatively associated with said valve and controlled by electrically operated retracting means, an electrically operated control valve in the branch conduit, a thermostat adjacent both burners, a switch operated by said thermostat, a second switch operated by the movement of the pressure responsive means independent of the valve, a control circuit including a source of power, the pressure operated switch and the branch conduit valve and a circuit in parallel with said branch conduit valve including the thermostatically actuated switch and the valve holder retracting means, a second switch actuated by the thermostat alternately with the first mentioned switch and an electrical igniter in circuit with said second thermostatically actuated switch.

9. In a combustion apparatus comprising a combustion chamber, a source of fluid fuel under pressure, a conduit from said source of fuel to said combustion chamber and terminating in a main burner, a branch conduit from said first mentioned conduit to said combustion chamber and terminating in a pilot burner, a valve in said conduit between the branch conduit and the main burner, pressure responsive means capable of opening said valve operatively associated therewith and having a limited movement independent of said valve, resilient valve holding means operatively associated with said valve and controlled by electrically operated retracting means, an electrically operated control valve in the branch conduit, a thermostat adjacent both burners, a switch operated by said thermostat, a second switch operated by the movement of the pressure responsive means independent of the valve, a control circuit including a source of power, the pressure operated switch and the branch conduit valve and a circuit in parallel with said branch conduit valve including the thermostatically actuated switch and the valve holder retracting means, a second switch actuated by the thermostat alternately with the first mentioned switch.

W. L. RIEHL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,836,268 McFarland Dec. 15, 1931 1,836,567 Wolpert et al Dec. 15, 1931 1,866,541 Branche July 12, 1932 1,975,656 Irvin Oct. 2, 1934 1,982,561 Williams Nov. 27, 1934 2,017,725 Newell Oct. 15, 1935 2,077,297 Williams Apr. 13, 1937 2,161,248 Denison et a1. June 6, 1939 2,200,908 Beggs May 14, 1940 2,214,558 Kronmiller Sept. 10, 1940 2,290,963 Higley July 28, 1942 2,305,242 English Dec. 15, 1942 2,305,243 English Dec. 15, 1942 2,361,530 Burch -1 Oct. 31, 1944 2,373,326 Miller Apr. 10, 1945 2,407,438 Newman Sept. 10,

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