US1710839A - Fuel-supply system - Google Patents

Description

APTIV3H'1929- l `T. A. PEEBLES y 1,710,839

FUEL SUPPLY SYSTEM Filed sept. s, 1925 Patented Apr. 3o, 1929.

UNITED STATES PATENT orifice.

THOMAS A. PEEBLES, OF PITTSBURGH, PENNSYLVANIA.

FUEL-SUPPLY SYSTEI.

Application llled September l the rate of flow of either ofthe fluids will vary and the proportions of air and fuel be .P

changed by any variations in the resistance to the flow of either fluidbetween the controllin valve and the burners. The air l5 which 1s usually assed through a preheating device such, olf-1A example, as a checkerwork is particularly sub]ect to this drawback, due to the fact` that such a preheating device becomes cloo'ged with dirt and foreign 2Q matter resulting fiom various causes.

An ob'ect of this invention is to provide a system or supplyino' fuel to furnaces of such construction andD arrangement that any variations in the resistance to the flow of fluid from the controlling valve to the burners will be so compensated for as to maintain theproper proportions and rate of flow of the iuids forming the fuel. l

A further object is to provide a system for supplying fuel vto furnaces having a means for maintaining a constant quantity llow of the fluids for any given setting of the valves, regardless of variations in the resistance to flow resulting from such a device as a checkerwork used for preheating air.

A still further object is to provide a system of the type set forth which will be simple to manufacture, easy to control and reliable and accurate in operation.

4o These, and other objects which will be apparent to those skilled in this particular art, are accomplished by means of this invention, one embodiment of which is illustrated in the accompanying drawing, which is a diagrammatic vlew of a fuel supply system constructed in accordance with one form of this invention., v

In the particular embodiment of this invention illustrated in the drawing, the system is arranged so as to automatically comensate for variations in the resistance to the flow of air from the controlling air valve to the burners in such a way as to supply the burners with a constant quantity of air despite any change in such resistance. Ob-

s, 192s. semi 1ro. 5434s.

viously, the same stem can be so arranged as to compensate or any variations in the resistance to the iiow of the fluid fuel such for example, as oil -or gas, but in view of the fact that the latter flows directly from the valve to the burners and `that the .air passesv through such devices as a fan and a preheating c eckerwork or the like, the latter will be subject to a varying resistance and the present description is, therefore, ap-

lied to a construction in which variations 1n esistance to the flow of air are compensated or. t

The diagrammatic illustration in the drawmgdlscloses a supply conduit 1, having any des1red form of valve, such, for example, as the butterfly valve 2, for varying the rate of liow of fluid fuel such as oil or gas from a source'of constant pressure (not shown) to the furnace burners (not shown).

, An air supply conduit 3 is similarly provided with a valve such as the butterfly valve 4' for controlling the rate of flow of air through the conduit from a source at atmospheric pressure and the two valves-2 and 4 may have their operating arms 5 and 6, respectively, connected by a connecting bar 7 or the like for unitary movement by any form of operating means such as the hand lever 8.

A fan 9, operated, for example, by a motor or turbine 10 draws the air through the connecting conduit 3 and passes it through a second conduit 11 to the preheating checkerwork 12 which may be of any well known construction. From the latter, the air is passed to the furnace burners where it is mixed with-the gas supplied through the conduit, and the valves 2 and 4 are so correlated that the fluids are delivered in such proportions 'as to form the most eicient combustible mixture. Opening or closing of the controlling valves 2 and 4 will cause a proportionate variation in the quantity flow of the fluids passing through the conduits to, the burners. v Y

After the furnace has been in use for some time,` the passages 'of the checkerwork V through which the air flows become clogged with dirt and other foreign matter, with the result that fo: a given amount of opening of the air controlling valve 4 a smaller quantity of air will pass, due to the increased resistance to such passage in the checkerwork. As a, direct result of this reduced flow of air, 11o

the most eliicient proportion of air to gas which is ultimately supplied to the burners is destroyed resulting in faulty,inefiicient operation.

I have found that this dilliculty 'can be remedied, and a constant quantity of air caused to ilowfor any given opening of the air controllin valve 4, by maintainin the pressure in t e air conduit 3 beyon the valve 4 constant, so that aconstant pressure drop is maintained across the air controlling valve. n

The preferred mechanism foraccomplishing this .result is illustrated in the drawing and consists of a second-valve 13, the operating 1ever,14 of which is connected-by a rod to a pressure, responsive valve regulator `16 such, for example, as the regulator, disclosed' in Patent No. 1,150,097, granted August 17, 1915, to Francis H. Brown. The

f regulator is conn#n ated to the air conduit `be tween the two valves 4 and 13 by a pressure tap 17 andis adjusted. so as to open and close 4 the valve 13 .and maintain a constant sub will tend to increase.

atmospheric pressure' in the air conduit bc` yond the controlling valve 4. ,It will thus be seen that in View of the fact that the air is supplied tothe conduit from a source' at atmospheric pressure, there will be maintained a constant pressure drop across the air controlling valve with the result that any variation in the opening'of the valve 4 will cause a pro ortionate variation in the quantity flow o air pastthe valve, through the' conduit and to the burners. For example,

as the checkerwork 12 clogs up so as to in erease'the resistance tothe air flow, the pressure in the air conduit 3 beyond the valve 4; Such an increase,

Yconduit-1 to the burners. A

however, will actuate the pressure responsive regulator 16 so as to open the valve 13 an amount just sufficient to com nsate for the increased resistance of the clleeckerwork 12. The result is the maintainingof a constant total resistance to air flow from the controlling valve 4 to the burners so that any given position of the valves 2 and 4 will pass a constant uantity of air and gas to the burners in t e x'nost eiicient proportions.

. Obviously, the` invention can be applied,

1f necessary, to the gas conduit but, ordi` narily, this will not be necessary, due to the fact that the gas flows directl through the so the invention is notlimited to systems using gas as a fuelbut, may be applied with equal advanaga to systems using other forms of fluid Having described the referred modification of this inventiornw atl claim as new and desire to secure-by Letters Patent is A fuel supply system for furnaces including a conduit. for delivering fuel thereto, a

conduit for supplying airthereto, a valve f,

for controlling the quantity of air flowing through said air supply conduit, a second valve located in said air supply conduit between said lirst mentioned valve and said furnace and means operated entirelyby the pressure in said air supply conduit between said valves for operating said second valve so as to maintain the total resistance from said first valve to said furnace constant for 'a iven flow.

n testimony whereof, I have hereunto subscribed my name this 31st day of August,

THOMAS A. PEEBLus.

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