US1561474A - Liquid-fuel burner - Google Patents

Description

Nov. 17, 1 25; 1,561,474

I. E. MCCABE LIQUID FUEL BURNER Filed April 5. i924 3 Sheets- Sheet 1 v INVENTOR. F/g] 59M 6. MM

BY f m A TTORNEYS.

Nov. 17, 1925'. I 156L474 l. E. MCCABE LIQUID FUEL BURNER Filed April 3. 1924 3 Sheets-Sheet 2 Z, i nu ullllll INVENTOR A TTORNEYS.

Nov. 17, 1925. 1,561,474

I. E. MCCABE LIQUID F EL BURNER 7 Filed April 5, 1924 3 Sheets-Sheet INVENTOR. 2 a MOW A TTORNEYS.

Patented Nova 11?, 1925.

V UNITED STATES IRA E. means, or orzr'caeo, rumors.

LIQUID-FUEL BURN application filed April 3, 1924. Serial No. 703,8e1.

To all whom it may concern:

Be it known that I, IRA E. MCCABE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Liquid-Fuel Burners, of which the following is a specification.

This invention relates to improvements in liquid fuel burners and more particularly to a mechanical safety control therefor.

Liquid fuel burners are replacing to a large degree the'burning -of solid fuel in furnaces of all characters, especially in furnaces for the heatin of dwellings and other buildings, being adapted to hot air, hot water or steam heating systems. The most practical and commercially successful heating systems of this kind utilizing liquid fuel burners at the present time include electrically operated means actuating the burner with a thermostatic control therefor to maintain the desired temperature in the building to be heated. It is not only desirable but usually required by fire regulations that burners of such systems used in means to cutoff the supply of liquid fuel should, from any cause, the burner fail to ignite, the flame become extinguished or in the event that unconsumed fuel flood the combustion chamber. 7

Heretofore the conventional means generally employed as a safety device for this purpose depended upon the weight of oil accumulated from the extinguished burner o close the oil supply valve or break the electric circuit or both, the accumulation being depending upon accomplished in a fixed receptacle which operated a float therein connected to the operating member of the valve or electric switch or in a movable receptacle. such a aeup, operated by the weightof the liquid accumulated therein to act directly upon the operating member of the valve or switch the ability of the receptacle to positively contain the liquid as it accumulated therein before functioning.

It is an object of this invention to provide a mechanical safety'device of this general character actuated by a flow of oil from the extinguished burner or from the combustion chamber that will function with a minimum volumne of the liquid therefrom, will act ndependently withoutretaining the flowing type of liquid provided with mechanical liquid and, in the case of a float operated device, without the buoyancy of the float remaining constant.

With this and other objects in view reference is made to the accompanying sheets of drawing illustrating a preferred form of this invention as applied to a conventional fuel burner system for heatmg purposes. It being understood that this device is adaptable to other types of such system, as well as other types of liquid fuel burners for other purposes and what minor changes may be made therein without departing from the scope of this invention.

In the drawings: a

Figure l is diagrammatical view of an oil burning heating system with the controls therefor.

Figure 2 is .an enlarged detail view of a float operated safety'device embodying this invention, partly in section.

Figure 3 is a similar view of another form of counter weight operated switch.

Figure 4 is a similar view of another form of float operated switch.

Figure 5 is a detail view of a four terminal switch tube which may be used in connection with the safety control.

To'illustrate an embodiment of this invention an oil burning heating unit and controls is graphically shown in Figure 1, in which the furnace 1 contains a combustion chamber 2 having an air conduit v8i leading therefrom to an electric motor 4 driving a blower fan with an oil pipe leading from a tank or other source of supply through an oil pump driven by the motor a or by gravity to an oil burner at the entrance of the air conduit with the combustion chamthe cial power line of. which lead A passes through one or more thermostatic switches 5 placed in the room or rooms to be heated, through a' furnace control switch 6 thence through a mechanicallyv operated safety switch 7 to one poleof the motor 4 while the lead B passes'directly to the opposite 018 of the motor, both leads passing 'filed Oct. 23, 1922, respectively.

through a hand thrown switch 8. While the control switches 5, 6 and 7 may be of any known type to perform the functions designated, it is preferable to use mercury tube snap switches such as are illustrated u on these drawings and which are fully descri 'ed in my prior pending applications 535,755 filed Feb. 11, 1922; 538,916 filed Feb. 24, 1922; 585,698 filed Sept. 1, 1922; and 596,408

' within the switch casing and extending therebeyond with a link 10 connecting the lever arm to the snap movement of the switch so that movement up and down of the free end of the lever 'will throw the switch to break and make the circuit. The safet switch may be of the type shown or may he provided with a four terminal switch tube shown in Figure 5 in which two of the terminals may be connected to a bell circuit so that when the motor circuit is broken the bell circuit will be closed to act as an alarm when the-motor is cut off or the terminals may be so connected in a relaycircuit sothat when the, current passing through the safety switch normally is insuflicient to cut out the motor or operate a valve the operation may be accomplished by the relay circuit.

In the form shown in Figure 1 a drain pipe 11 is provided leading from the bottom of the combustion chamber 2 so arranged that should the oil from the source be supplied and the burner fail to i nite, be extinguished or the chamber be ooded from any cause, the oil accumulated therein will lead through the drain pipe to a mechanical safety device that will actuatethe operating lever 9 to throw the safety switch to break the circuit. This actuating means comprises a receptacle 12 carried upon the free end of the operating lever and preferably rigidly secured thereto. This receptacle is provided with a siphon 13, shown in dotted lines so arranged that as the oil from the drain pipe 11 causes the level of the oil in the receptacle to rise above the upper bend in the siphon, the siphon will operate to empty the receptacle. The operating 1ever9 is connected to a counter weight 14, by a link 15, of sufficient size to raise. the empty rece tacle and operating lever to the position s own in dotted lines nd thereby throw "he snap switch to break the circuit. To close the circuit a sufficient amount of oil or any other liquid is poured into the receptacle 12 to to start the siphon, and cause the receptacle and likewise the lever 9 to assume its lowermost sition, throwing the sna switch to close t e circuit. The open end 0 the siphon 13 within the receptacle is preferably arranged near the bottom of the receptacle with the bend below the top thereof. It is preferable to rovide a drippan 16 in the floor below t e exterior opening of the siphon of suflicient size to catch the liquid dlscharge therefrom which pan may ifdesired, be connected to a drain in the floor leading to the sewer. The discharge end of the combustion chamber drain is so arranged in relation to the receptacle that it will be cleared as the receptacle is emptied and swings upward by the influence of the counterweight in which position it will re-' main until manually moved to its lower position and sufficiently filled to remain there, in the meantime any further discharge from the oil drain 11 will be caught in the pan 16.

The siphon 13 must be of greater discharge capacity than the discharge of the drain pipe 11 to function and reduce the level of the liquid in the receptacle. A

overcome the counter weight, but insufiicient safety device of this character has a wide range of operativeness depending upon the level of the liquid contained therein when placed in operative position. The sensitiveness increases as the level approaches the top of the bend in the siphon, it may be initially set to operate only after a considerable oil has flowed from the combustion chamber to such a nicety that the flow of a single teaspoon from the combustion chamber will operate the siphon and thereby the switch, the flow beyond that point being immaterial as the siphon dischar es more rapidly than the drain pipe from t e chamber and as the discharging receptacle is moved from under the drain pipe all excess discharge therefrom is caught in the pan 16. Furthermore should the receptacle become damaged and leak, while the oil at the burner is in flame and operating, as soon as the receptacle is drained to a point to become possibly imperative the counter weight will operate the safety switch to break the circuit, thereby forming an additional safety device for the burner.

From this illustration and descriptionit is readily seen that the operation of this safety device depends upon a fiow of oil from the combustion chamber and isindependent of the amount or duration of such flow the quantity required to operate it depending upon the nicety of which it is originally placed in operatlveposition and further the evaporation or leakage of the liquid holding it in operative position will cause l*ig1l1'c 1 will shut off the burner.

In case it is desirable to employ a float operated switch a stationary receptacle 20 is provided, see Figure 2, which may rest upon the floor with a combustion drain pipe 21 leading directly into the top of the receptacle and a siphon 22 arranged exteriorly thereof leading from the bottom of the receptacle and discharging into a drain 23 in the floor leading to the sewer, with the siphon discharging more rapidly than the.

drain pipe 21 and the top bend of the siphon below the entrance of the said drain pipe into the receptacle. A float 2% is arranged within the receptacle which will rise and fall with the level of the liquid contained in the receptacle and is provided with a stem 25 which may be connected to the free end of an operating lever such as lever 9 above described with the mercury tube reversed as shown in Figure l or to a valve 26, as hereinafter described. In either casesufficient liquid of any kind is placed in the receptacle, preferably by pouring on this funnel like closure 27 of the top thereof, to raise the float sufiici'ently to close the circuit or open the valve to operate the burner.

Upon flow of'oil from the combustion chamher through the drain pipe 21 into the receptacle the level of the liquid therein will rise until it reaches the top of the bend in the siphon, as indicated by the dot and dash line, Figure 2, when the siphon will discharge and. lower the liquid to the level as shown, the weight of the float arranged to be sufficient on its descent to throw the switch or close the valve. The normal operative position of the float being supported in the liquid of a level between that which will close the circuit or open the valve and the level of thedot and dash line.

The construction shown in detail in Figure 2 is a float operated valve in the supply pipe 28 leading from a source of oil on the left, not shown, to the burner on the right, not shown, in which the valve head 26 carried on the end of the float stem 25 is arranged to be raised above the seat 29 in the valve so interposed in the oil line by the float when in normal operative position and to be closed upon said seat and cut off the' oil supply to the burner when the float is lowered by the discharge of liquid from the receptacle caused by a flow of oil from the combustion chamber.

It may be desirable to provide an intermittently operating safety device, especially where an electric ignition system for the burner is employed and when the spark therefrom does not ignite the oil at the burner initially, or when the combustion chamber is cold. i

A device of this character is shown in snap switch construction of the same type as shown in Figure 1 with a counter weight 32 arranged on the lever at the other side of the pivot and within the casing. This lever is preferably connected to the snap mechanism of the switch by an arm 33 extending from the lever between the counter weight 32 and pivot having an undulating surface on one side thereof coacting with aroller mounted on one end of a member 34E pivotally carried on-the snap movementwith a counter weight on the other side thereof causing the member to maintain contact with said undulating surface of arm 33 which forms a shoulder 011 both sides of said roller when the snap movement'has been thrown in either direction, the counter weight 32 and the depression of the'free end of the lever 31 carrying the roller to first impart the adjacent shoulders.

The snap switch being in circuit with movement to the snap mechanism the motor, as shown in Figure 1, and initially filled with sufficient liquid to depress the lever 31 to close the circuit, and the spark of the electric ignition fails to initially ignite the oil at the burner, the unconsumed oil will ow from the combustion chamber through drain pipe 35 into the receptacle causing the level of the liquid to rise until discharged from the receptacle by I the siphon 36. The counter weight 32 will then throw the switch to break the circuit and cut off the motor, however, the receptacle in this case is pivoted to this lever 31, so that in its upward movement the receptacle still remains under the discharge end of the drain pipe 35 so that if the oil still flows from the combustion chamber, after the motor is cut off and the receptacle siphoned ofi', it will upon the failure of the siphon again raise the level of the liquid in the receptacle which will, if the oil continues to drain, overcome the counter weight 32 to close the circuit to allow the spark of the agnition system further time to ignite the oil at the burner and then operate as at first described should the burner fail to be ignited or later become extinguished. Inthis case the pan 37 is arranged below the receptacle to receive the oil discharged from the siphon.

At times it may safety same time the supply of oil to the burner orthe supply of oil or gas to a pilot light for the burner independent of the motor. Such a device is shown in Figure 4 and com= be desirable to provide a prises a float operated arrangement similar to that; shown in Figure 2 with the stem 25 of the float pivotally attached to the device to cut off the motor and at thefreeends of o crating levers 40 and 41.

I Lever 40"exten s from the casing 42 or a mercury tube snap switch in circuit with the motor, is pivoted therein and connected by a link 43 to the snapmovement, the mercufigtube so arranged that the circuit is closed upo the upward movement of the lever 40 and opened upon the downward movement thereof. Lever 41 enters into a valve casing 44 interposed in the oil line 45 to the burner or gas or oil line'to the pilot light for the burner, as the case may be, with the gas or oil flowing from left to right throughlthe valve casing. The valve head 46 is provided with a sliding connection with the interior end of the lever 41 so as to be. unseated and open upon the upward movement of the exterior end and close and seated upon the downward movement thereof.

In this figure the float 24 is shown in the operative, position with the exterior ends of levers 40 and 41 in raiseil positions closing the circuit through the snapswitch to the motor and opening the oil or gas pipe to the burner or pilot light, liquid havin been introduced, to the level shown, int c receptacle. Upon failure of the burner flame.

from any cause or upon the flooding of the combustion chamber the unconsumed oil will flow from the chamber through the drain pipe 21 into the receptacle 20 until its level therein is above the top of the bend in the siphon 22 which will then operate to discharge into drain 23 until the level is reduced to the end of the siphon. near the bottom of the receptacle causing the float to move downward with the liquid moving the exterior ends of thelever 40 and 41 at the same time to break the circuit of the motor and close the oil or gas valve in unison. In

. this form the drain .pi e 21 is shown discharging into the funne sha. ed cover 27 of the. receptacle and asses t rough the en-- larged opening for t e valve stem.

In these float operated devices shown in Figures 2 and 4 the movement of the floats is limited by the bottom of the float resting upon the bottom of the receptacle in its. downward movement and the top of the float engaging the under side of the funnel shaped top cover 27 The normal operative position of the float is reached by pouring liquid into the receptacle until the, top of the float contacts with the top float 27 which can be observed through the opening therein of the-float stem .or through apertures provided-for that purpose. If there is any .buo anc at all in the float it will operate.

If t e float has been damaged or leaks until it becomes water logged it will not rise when liquid is poured into the receptacle and such ,placed in operative position.

In case the float is arranged to control the operation of a pilot light for the burner it may also operate a means for diverting further flow of unconsumed oil from the combustion chamber to the floor drain after the pilot light valve has once been closed to prevent its operating intermittently.

' To insure the positive operation of the siphon it is preferable, particularly in siphons of large diameter, to provide a liquid seal at the discharge end either in the form of the cup 47, as illustrated in the drawing,

or by bending the discharge end upward in what is known as a goose neck 48, as shown in Figure 3, whereby suflicient liquid is retained in the siphon tube to form a seal for that end. As illustrated a cup or receptacle 47 is attached to the discharge end of the siphon 13 extending upwardly and thereabout to form a seal confining the air in the tube 13, allowing only the excess pressure to escape as the level of the liquid in the siphon connected receptacle rises, so that when the level has reached a point above the bend the liquid therein will positively siphon out.

What I claim is: v

1. In a liquid fuel burning furnace including an electric circuit operating a motor supplying fuel to the furnace and having a room thermostat and .furnace control switches in circuit therewith, a burner directing its flame into a combustion chamber within the furnace, a drain pipe for leading the unconsumed fuel from said chamber, and a safety control switch inthe said circuit in combination with a liquid containing receptacle normally maintaining the safety switch in closed position when partially filled and into which the drain pipe discharges, means in connection therewith operated by a flow of liquidfuel from the drain pipe to empty the receptacle, and means operable when the receptacle is empty to open said safety switch and thereby cut off the supply of fuel to said burner.

2. In aliquid fuel burning furnace including an electric circuit operating amotor supplying fuel to a burner directingits flame into a combustion chamber within the furnace with room thermostatic and furnace control switches in circuit therewith, a drain pipe leading unconsumed li uid fuel from the combustion chamber, and a safety control switch in said circuit in combination with a liquid containing receptacle maintaining the safety switchin closed position and into which the fuel drain pipe discharges, a siphon in connection with the said receptacl operated by a flow of liquid from the drain pipe, and means for throwing the safety switch when the receptacle is empty to break the circuit and thereby cut off the supply of liquid fuel to the burner.

plying fuel to the furnace and a drain pipe leading the unconsumed fuel from the furnace, a safety switch in circuit with the mo- I drain discharging into said receptacle, and

means therein operated by a flow of liquid from the drain tonlessen the weight thereof to allow the safety switch to be thrown into its normal open position and thereby break the motor circuit and cut off the-supply of fuel to the burner.

4. In a liquid fuel burning system for furnaces having an electric motor for supplying fuelto the furnace, a drain for unconsumed fuel leading therefrom, a thermo-' drain to empty the receptacle, and means associated with the switch to allow the switch to be closed when the receptacle is partially filled and to open the switch when the recepta'cle is empty. a

7. In a liquid fuel burning system for furnaces having an electric motor for supplying fuel to the furnace and a drain for leading unconsumed fuel from the furnace, a thermostatic switch controlling the operation of the motor, and a safety switch in circuit with the motor, a liquid receptacle arranged to receive the discharge from the drain, a siphon adapted to be operated by a flow of liquid from the drain to empty the receptacle, and means associated with the switch to allow the switch to be closed when, the receptacle is partially filled and static switch controlling the operating oft to open the switch when the receptacle is the motor, and a safety switch in cireiiit with the motor having means arranged to throw the switch to the open position" and a weighted means normally acting in opposition thereto to close the switch associated with means lessening the weight of said means operated by a flow of liquid from said drain allowing the safety switch to be opened by the first means andthereby cut off the supply of fuel to the furnace.

5. In a liquid fuel burning system for furnaces having an; electric motor for supplying fuel to the furnace, a drain leading unconsumed fuel from the furnace, a furnace control switch in circuit with the motor.

and a safety switch insaid circuit having means arranged to open the switch, and a weighted means in opposition thereto to close the switch coacting with a flow of liquid from the drain to lessen the weight of said opposing means and allow the switch to be opened by the first means and thereby cut ed the supply of fuel to the furnace.

6; In a liquid fuel burning system for furnaces having an electric motor for supplying fuel to the, furnace ,and a drain for leading unconsumed fuel from the furnace, a safety switch in circuit with the motor. a

a liquid receptacle arranged to receive the discharge from the drain, a siphon adapted to be operated by a flow of liquid from the p y- 8.111 a liquid fuel burning system. for furnaces having an electric motorfor supplying fuel to the furnace and a drain for leading unconsumed fuel from the furnace, ",a' furnace control switch in circuit with the motor, and a safety switch in said vcircuit, a liquid receptacle arranged to receive the. discharge from the drain, a siphon adapted to be operated by a flow of liquid from the drain. and means associated with the switch to allow the switch to be closed when the receptacle is partially filled and toopen the switch when the receptacle is empty.

' 9. A. safety device for oil burning systems having aisupplv of oil to a burner and a drain for leading unconsumed oil therefrom, comprising a receptaclenormally partiltv tially filled with liquid arranged to receive the discharge from the drain, a siphon in the receptacle. 4

3 IRA McOABE.

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