US2369746A - miller - Google Patents

Description

20, 1945- E. c. MILLER GAS HEATING APPARATUS Filed March 1, 1941 5 Sheets-Sheet 1 INVENTOR 'ATTORNEY -GAS HEATING APPARATUS Filed March 1, 1941 3 Sheets-Sheet 2 60 Y Q- 3-LAA2 $3 9 AlgVENTOR ZTTTORZEY I Feb. 20, 1945; c E 2369,746

GAS HEAT ING APPARATUS Filed .March 1, 1941 s Sheets-Shet s v flw Fig.5.

INVENTOR m v ATTORNEY i advantages of portions in section;

combustion "from? thethroughthe radiator and'thence through the fan into a discharge conduit: Arr air-gas fuel mix I Patented Feb. 20,1945

'I'hisinventionrelatesto gas burning heating 1,510,475 relates, andthelpresentinvention con-Z stitutes an improvement thereon.

One of the objects er the inventionis to provide an improved iorm'of gas burner device which Iop'erates with increasedefficiency and safety. Another object of theinvention isto provide a control system for gas burner devices of the character described which functions in a novel and of an appropriate" proportion of gas into the burner headto be mixed with the airfthereini and the gaseousproductsof thejoornbustion proo ess then flow through ,theradiatorjlfl and the conduit l5,and thence-throughthe fan 2i) to be discharged thereby throughfa suitable discharge mproved manner to "provide improved starting and. stopping performance. Other objectsand heiinvention will appear fro nthe specification herein. j

"In the drawings: y I Fig. 1 is an elevation'of' a gas burning heater device of the invention; 1

scale taken substantiallyfalong line 11-11 of Fig.

1', showing portions-of the air-gas mixing device and combustion chamberlin 'elevation'and' other Fig. 2 is a'fragmentaryview on an enlarged" Fig. 3fis"a fragrnentary section taken' substan-.

' tially along line III' -III of'Fig. 2; and

- Fig. 4 is a fragmentary section taken substantially, along 'line"I-V+IV of '1 'and 'showing the interior of a detail thereof. i

Fig. :5 is ai fragrnentary 'section of the fuel tube of pressure Fig. 6 is a fragmentarysection regulator device of Figsil and 2."

' As illustra ted -in Fig. ll-the inventionis applicable to a gas burning device comprising-generally, in combination, 'a'fheat transfer radiator lllj 5 a suction fan 20;" a combustion chamber an r air-gas mixing device '40; and 'a ruel flow con- ,trolsystem as will be described infdetail;hereinafter. i

The combustion chamber and the radiator and the suction-fan elementsiare interconnected to provide for movement -"of the gaseous products" of combustion chamber tureisindu'ced to fiowinto the combustion chain-'- her through an -automatic,; valve mixing device which delivers the fuel-to a burner head 10-"- cated in- -the lower portion of the combustion chamber by'the action-of -the suction fan;.pthe air forthe mixture being taken either from the atmosphere'in the neighborhood of the heating v unit or from some-'i'em'ote-point through asuit able inlet conduit 41-, .=The partial vacuum creconduit (not shown) In the drawingsthe radiator lo is; shown as I being of the well known sectional type; but'it will be understood. that'tn invention is adapted to use in connectionwith' any'other suitable' form of hot gas conveying heat exchange ,devic'e. Ports ll in lower walrportions of thek radiator sections lead into the conduit ,I 5,whichleads into the intake openingpf, the fan 20.: The combustion chamber aonem nses. essentially, a box-like. casing 3! located centrally of -andf-in the upper portion of the 'radiator unit; and i'n'tercommu nicating"conduitsjtlare provided between the interiorsof the radiator sections and the combustion chamber. A door 33 is hingedly mounted upon aside wall ortion of the cornbustioncham ber casing to provide. access into the interior thereof whenever necessary. i The burner headl35,may beof any suitable type and is illustrated as comprising aflaring tube 36 with an end'closure'plate 31 in which are pro{ vided 'aplurality ofjet openings 38 to provide evenly distributed flow-.of fuel over the area of the burner head. 'The lower end of. the burner headis connected in open communication with the upper end of a fueltubeflfl which extends through the'lower wallportion of the combustion chamber casing}! and into communicationwith the interior oitheairfgas mixing'device casing 44 by means of an elbow.45, for transmission oi I fueltherefrom tothe burner head.

The air inlet control device of the inventi on includes a valve 50 disposed within the casing 44.

* and adapted to seat upon a partial partition'wall ated withirithe combustion chamber by the 8.0-

tlon of the fan '20 also operates to induce -;flo.w.=

portion 54 of the valve casing 44 to regulate. flow of'airthrough the casing from an air inlet conduit 4| to, the fuel tube 39,- The'valve to is mounted. upon ahvalve stem .52 which is slir llabll.vv mounted upon thefica'sing 44. by' means of suitable slide bearings 5'lfand5i8 (Rig. 3). A fluid pressureresponsive diaphragm 62. is'rnounted within a casing64 which also encompasses the lower end of the Valve stem 52. ,The casing 64 is open to the atmosphere underneaththe diaphragm 62, as

at 66, and abovethe-diaphragm is arranged 'in open communication with a vacuum" conduit 68 (Fig. 2) which leads from a vacuum valve chamber 89 which-inturn isin open communication communicated, thereto through said conduit 10.

A vacuum control valve I2 is disposed within the vacuum chamber 69 and is adapted to seat upon a partial intermediate partition wall 14 thereof. The valve I2 is mounted upon a valve stem 16 which extends into the interior of a sole- 1 noid winding I8 and is adapted to function as the armature thereof. The solenoid 18 is so arranged as to be adapted to draw the armature stem 16 upwardly under closed circuit conditions so as to unseat the valve 12, thus permitting fiow of air through the conduit tube into the combustion chamber under the suction force of the fan, and the partial vacuum will then be projected into the portion of the casing 84 that is above the diaphragm 62. Consequently, the air under atmospheric pressure admitted through the aperture 66 of the diaphragm casing will exert pressure against the bottom surface of the diaphragm 62 that will overcome the pressure against the top side thereof with the result that the diaphragm will move upwardly and the plate 60 will press against the valve steam 52 to raise the latter vertically so that the valve 50 will be unseated and.air will be admitted from the conduit 4| through the valve casing and into the fuel tube 39. Whenever. the solenoid 1,8 is de-energized, however, the force of gravity operatesto cause the valve I2 to lower upon its seat thus cutting on the vacuum above the diaphragm 62. A small aperture II is formed through a wall portion of the casing 'of the chamber 69.so as to permit a slight bleeding of air at this time into the vacuum chamber and above the diaphragm 62 so that the atmospheric pressures at opposite sides thereof become equalized upon closing of valve 12. Consequently, the diaphragm plate 68 lowers under the force of gravity to permit the valve stem 52 to return to valve closed position. In this respect, particular attention is called to the fact that because of the valve stem arrange ment of the invention the gas control valve 82 will close prior to the closing orthe air control valve 50, and that this mode of operation provides advantages as will be explained in detail hereinafter.

A second valve stem 80 mounting a gas inlet control valve 82 is disposed in vertical alignment with and above the valve stem 52. The valve 82 is disposed within a gas inlet chamber 84 which is in open communication with the gas inlet conduit 42 and mounted upon the valve casing 44 in open communication with the interior thereof. A transverse annular partial wall 86 is arranged to provide a, seat for the valve 82, and the parts are so proportioned and arranged that when the valves 82 and 50 are seated there is a substantial gap as at 88 between the two valve stem members. Thus, when the valve stem 52 is first raised by the diaphragm 62 to lift the valve 58 from its seat the valve 82 remains in gas sealing relation upon its seat. However, as the stem 52 is further lifted under the diaphragm pressure stantially that determined by the fluid pressurev closes the gap between the two valve stem members and the stem allsubsequently raises to open the valve 82 whereupon gas from the conduit 52 flows into the valve casing 44 and thence into the fuel tube 39, mixing with the air being admitted thereinto as hereinabove explained.

The operation of the device is automatically controlled by means of a thermostat device I80 which maybe of any suitablev room temperature control type electrically connected into the circuit controlling the solenoid 18. Thus, as long as the temperature of the atmosphere adjacent the thermostat Hill is lower than that called for .by the adjustment of the thermostat under any given condition, the operating elements of the thermostat will remain in circuit-closed condition and the solenoid I8 will maintain the valve I2 above its seat, thus allowing the diaphragm 62 to maintain the valves 58 and 82 in open'position for-fuel delivery purposes. Upon attainment of the desired temperature of the atmosphere surrounding the thermostat 108 the actuating elements thereof will move into circuit open position and the solenoid 18 will be de-energized thus allowing the valve 12 to move downwardly to closed position, whereupon the diaphragm 62 will withdraw from contact with the valve stem 52 and allow the valves 82 and 50 to assume closed positions, thus cutting off the supply of fuel and air to the burner head. As explained hereinabove, during the movements of the valve members 82 and. 50 toward closed positions the valve 82 will reach its seat some time prior to the closing of the valve 50. Thus, upon termination of the flow of gas into the fuel tube 39 there will be a further fiow'of air thereinto to scavenge the burner head of any unhurnt gas that might otherwise remain therein. By reason of this feature of the invention it will be understood that the danger of accumulation of unburnt gas in the working parts will be eliminated.

Upon movement of the actuating elements of the thermostat I80 to circuit closed position the solenoid 18 will be energized and the valves 5t and 82 will be caused to open in the order named. as explained hereinabove. Thus, a supply of air will first be introduced into the burner head and combustion chamber, and then a flow of gas will be added thereto. As a result of this mode of gas introduction the danger of gas explosions during the ignition period is avoided.

A constant burner tube H0 is provided in conjunction with the apparatus and so arranged as to have its outlet end adjacent the burner head 31 and its intake end in open communication with a gas inlet tube H2, and with an air inlet tube H4 (Fig. 3). The air inlet tube H4 is in communication at its other end with the interior of the air conduit ll, and the gasinlet tube H2 is in open communication with a main as supply conduit H5 (Fig. 2). As shown in Fig. 2, the pressure-in the gas supply conduit H6 is automatically regulated by means of a suitable pressure regulator H8 so that the gas delivered therefrom into the primary gas conduit 42 and into the constant burner conduit I I2 is of constant pressure. An adjustable needle valve 22 is provided in 'the line of the conduit H2, and a similar valve I22 is provided in the line of the conduit 42, for independent adjustment of the flow of gas therethrough. Thus, it will be understood that the constant burner tube H8 is normally provided with a constant supply of mixed air and gas, and therefore a pilot light will reaces-arc main 'burning the burner head 35; to provide ignition ct -the main fuel supply passing therethrough 'upon re-starting operationskoi the thermostat control device."

f Asillustrated in Fig; .1, the outlet end of the constant burner-tube 110 is disposed within th'e burner head 35 and centrally thereof. In transthe valve stern 52lallowingfirst-thergasvalve '82 verse section the constant burner discharge end is provided with'ta iaterally'directe'd extension HII (Fig. 2) .so asto dischargelthe-constant burner fuel againsta substantially centrally located portion of the burner head plateB'l. Thus,v upon startingiof the main fuel burning operationthe fuel streamrising through the .fuel tube 3.9 will substantially envelop the flame of the constant burner, and thus an improved tion will be-obtained. I I

' A safety control valve 130 is connected .in the form of fuel igni I line of the main :gasxsupply conduit H6 and is arranged to be actuated'in response to operation of a thermocouple l32(Fig. '2) disposedwithin the combustion chamber 30 and adjacent'the constant burner flame. Thethermocouple device" is operatively associated with the moving parts of the valve I30 ,by' means of interconnecting wiring I34 and is so arranged that as long as the constant burner is in operation the'thermostat device' lfnfl' reaches the desired temperature the circuit-to the' solenoid 18 is opened, thusizallowing the valve stem 75 to moveidownwardly to seat the valve 12. Consequently, the pressures at opposite sides of the diaphragm 62become equalized and the plate-"8U withdraws from to close andsubsequently the air valve 50 to close, whereupon only the constant burner remains in operation for repetition of the process as may berequired by the thermostat device.

I resulting in the closing of the main air-gasvalVS couple device maintains the safety valve 131! in open condition. However upon cessation of the constant burner operation, as upon failure of the gas supply,.. the thermocouple operates to actuate the safety valve to closed condition, thus eliminating the danger of having thecombustion chamber subsequently filledwith unburnt gas. upon resumption "of the gas-"supply and in the absence of igniting means.- A manually operable valve opening button I36 is provided in conjunction-vviththe valve I30 to permit manual reopening of the gas supply circuit preparatory-to I re-starting the device subsequent to complete interruption of the service.

To operate the apparatus;of the-invention; it will first be started by closing the" power switch I to'the fan '20, thus creating a partial vacuum throughout the combustion chamber-radiator system. The thermostat 1001s then set to the desired temperature, and thegma'in supply gas valve H! is opened. The combustion chamber door '33is then opened;a'nd"this destroys the partial vacuumin the t; combustion chamber whereupon the main gas and air inlet control valves 82, and 5G assume-closed positions. .IThe button 36 of the safety control valve I is then manipulated to permit a'slight'flowof gas therethrough-into the constant burner tube] Ill where it mixes with aflow of air entering fr'om the air inlet conduit M A burning taper is then-applied to the burner head to'ignite thefuel stream,

and the button I3B' is manually maintained in valve open position until such'time as the heat of the fuel burningoperation causes the elements 30 in open position without assistance.

"and if the adjustment to the; thermostat- 100 calls for an increase 'inthe temperature bfthe atmosphere thereabout the circuit coi'itrollingthe solenoid 18 is closed and the valve 12 will lbe lifted fromitsseat and thus in turn cause the diaphragm-6'2 toopen successively the air and gas valves --59 and 82, whereupon flow of fuel through the'main burner tube will commence.

As itemerges from the burnerit ignites from-the flame of the constant burner tube.

, of the thermocouplelfi fl'to maintain the valve The combustion chamber dooris then closed,

7 When the atmosphere adjacent the thermo- 'Asafurther safety feature of the invention, a thermostat device We is mounted upon the fuel tube 39. The thermostat M0 comprisesessentia'lly a benthi-metallic element 142 (Fig. 4) -6X- tending into the interior of the fuel tube 39. The endportions of the element M2 normally contact electrical connection devices [44 to close the circuit to the solenoid operated valve 12 Upon flashback of flame into the interior of the jfueltube 39 the bi-metallic element -isheated and-deflects to break the' circuit to the solenoid stantial distance into the interior of the "tube ill) and having a reduced orifice H in the end thereof. The'air inlet tube H 4' is' tapped into the constant burner tube 1 l0 at a position adjacent the tube 1 62. .Thus,'un'der normal operating conditions, the partial vacuum i nthe burner tube H0 draws air through tube 114' to ben'iixed with the gas issuing through the orifice IB'Ofor pilot burner operation, The-rate of air flow through the tube H4 is arranged to be adjusted by'means of a set screw 54 (Fig. 2'); the inner end'of which is adapted to be moved'into and out of engagement with the inletendlof the tube H4 to control the flow of air th'ereinto'. However, under interrupted electric powerconditions the partial vacuum in the tube HE: is no longer available for drawing therequired amount of air through the tube H l to providea blue flame at the constant burner head, and to meet this condition I provide an auxiliary air inlet port- I adjacent the jet ltd. The auxiliary air port-l'm-is normally closed by meansof a cover disc I12 adapted to function in the manner of a check valve under the action of suction within the tube H0, but

under 'fan-ofl conditions when suction in the burner head is absent the disc I72 is adapted to fall away from the port; H0 under the. force of gravity as to the broken line position shown in Fig. 5. Consequently, the flow of gas through theorifl'ce lEiloithe jet I62 will now operate in the manner of an inspirator to induce a flow of air 4 through the imletport i'illso that a proper mixture, of'ga's' andair will be obtained wherebya blue flame burning operation is obtained under all conditions of pilot burner operation.

1 The pressure regulator device H8 is of special form as illustrated in Fig. 6 and is shown therein "as comprising generally ahollow casing 8 8d enclosing ayflexible diaphragm I 32. The gas conduit H6 opens into the casing I30 :b'elowthe diaphragm 182,.and-the.casing is ventedas; atilii l was to permitgradual bleedin'g ofair from the diaphragm and normally pulls the diaphragm downwardly to maintain the valve ISO in open position. However, whenever the pressure in the gas conduit l3! raises or lowers from the desired standard the effect thereof is immediately transmitted to the diaphragm I82 which accordingly either raises or lowers to partially close or further open the valve I90, whereby the rate .of flow of gas into the conduit H6 is kept uniform at all times.

As illustrated in Fig. 1, an automatic vent device I95 is provided in an upper wall portion of the casing 3| and is so arranged that the disc member thereof falls forwardly to vent-open'position upon stoppage of the fan 20, as under power interruption conditions. Consequently, the products of combustion from the constant burner are free to escape through the vent I95 and do not accumulatein the combustion chamber to snufi out the constant burner. Upon current resumption the suction of the fan reseats the vent disc and the products of combustion are then drawn through the radiator and expelled as explained hereinabove.

Attention is called to the fact that the gas-air inlet arrangement of the invention is of such form that whenever the thermostat control device is at off position the valves 50 and 82 are both closed. Consequently, although the suction fan is continuously in operation, there will be no flow of cold air through the combustion chamber and radiator unit under burner-off conditions such as would otherwise cool off the combustion chamber and radiator between each burning stage of operation. Consequently the heat previously stored in the combustion chamber and radiator structures is not wasted as would otherwise be the case by absorption thereof into the cold air stream passing through the combustion chamber and radiator structures and being discharged by the suction. Attention is also called to the fact that under burner o conditions the operation of the constant burner device is carried on under ideal conditions and without introduction of excessive amounts of air into the system. Consequently, the velocity of movement of air-gas mixtures through the system under such conditions is relatively slow, and the heat generated by the constant burner operation is fully utilized and transferred to the radiator heat exchange portions and thus usefully employed.

Although only one form of the invention has been shown and described in detail, it will be apparent to those skilled in the art that the invention is not so limited but that various changes may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim: 1. In gas burning heating apparatus of that class in which the heated gaseous products of combustion are withdrawn from the combustion chamber of the apparatus through a heating radiator by a constantly operating suction device whereby combustion of thegas occurs under condltions of subatmospheric pressure, a burner disposed within said combustion chamber and a conduit adapted to convey mixed gas and air to said burner, a gas valve controlling the admission of gas into said conduit, an air valve controlling admission of air into said conduit, a fluid pressure responsive movable element for actuating said valves, both said valves being of the poppet type and being relatively so spaced and so disposed in substantially longitudinal alignment that said air valve may be opened to a predetermined extent independently of any movement of said gas valve and further movement of said air valve will effect engagement between an element thereof and an element of said gas valve, to move said gas valve to open position, and mechanical means to transmit operative movement of said fluid pressure responsive element to said air valve and upon continued movement of said air valve to effect opening movement of said gas valve and said valves adapted upon a recessional movement of said actuating element to be restored in reverse order successively to valve-closed position, and controlling mean to intermittently effect communication of the fluid pressure in said chamber to said element whereby said element may be intermittently operated under conditions of subatmospheric pressure in said chamber, and means to retard the speed of movement of said element, to increase the length of the period between successive operations of the successively moved valves.

2. In gas burning heating apparatus of that class, in which the heated gaseous products of combustion are withdrawn from the combustion chamber of the apparatus through a heating radiator by a constantly operating suction device whereby combustion of the gas occurs under conditions of sub-atmospheric pressure, which have a. main gas burner and a constant pilot burner which is disposed adjacent to said main burner, the combination of an air and gas mixing valve mechanism for providing a combustible mixture for said burner, said mechanism comprising separate gas and air inlet valves and a movable valve operating element adapted to be intermittently actuated upon controlled intermittent communication thereto of sub-atmospheric pressure prevailing in said chamber, me-

chanical means to transmit an initial portion of the movement of said element to said air valve and to transmit a subsequent portion of such movement to said gas valve to effect sequential opening of said air and gas valves, and said valves adapted to be successively re-closed in reverse order upon recessive movement of said element, and means to retard the speed of movement of said mechanical "means, whereby scavenging air will alone b supplied through said air valve to said main burner during the period intervening between the successive openings of said valves, and the period intervening between the successive closures of said valves.

-3. In gas burning heating apparatus of that class, in which the heated gaseous products of combustion are withdrawn from the combustion chamber of the apparatus through a heating radiator by a constantly operating suction device whereby combustion of the gas occurs under conditions of sub-atmospheric pressure, which have a main gas burner and a constant pilot burner which is disposed adjacent to said main intermittently actuated upon controlled intermittent communication thereto of sub-atmospheric pressure prevailing in said chamber; me-

chanical means to transmit the movement of said element to said valves whereby a combustible mixture is supplied to the burner, and said element adapted upon thev recessive .movement thereof to successivelyreclose said valves, said gas valve being first reclosed, and means to retard the speed of movement of said element to increase the length of the period between the closure of the gas valve and the closure of the air valve.

4. In gas burning heating apparatus of that class, in which the heated gaseous products of combustion are withdrawn from the combustion chamber of the apparatus through a heating radiator by a constantly operating suction device whereby combustion of the gas occurs under conditions of sub-atmospheric pressure, which have a main gas burner and a constant pilot burner which is disposed adjacent to said main burner, the combination of an air and gas mixing valve mechanism for providing a combustible mixture for said burner, said mechanism comprising separa'te gas and air inlet valves and a movable valve operating element adapted to be intermittently v actuated upon controlled intermittent communication thereto of sub-atmospheric pressure prevailing iri saidchamber, mechanical means to transmit an initialportion of the movement of said element to said air valve and to transmit a subsequent portion of such movement to said gas valve to efiect sequential opening of said air and gas valves and said valves adapted to be reclosed upon recessive movement of said element, and meansto retard the speed of movement of said mechanical means, whereby scavenging air will alone be supplied through said air valve to said main burner during the period intervening between the successive openingsof said valves. I

- ERWIN C. MILLER.

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