US2494714A

US2494714A - Oil burner apparatus, including an automatic delay action fuel valve

Info

Publication number: US2494714A
Application number: US480725A
Authority: US
Inventors: Wallace R Lyman
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1943-03-27
Filing date: 1943-03-27
Publication date: 1950-01-17
Anticipated expiration: 1967-01-17

Description

N OIL BURNER APPARATUS INCLUDING AN AUTOMATICDELAY ACTION FUEL VALVE Janflv, 195o w R YMA 2,494,714,L

Filed March 27. 1945 2 Sheets-Sheet 1 \1 Bis-s L iirfgi s4- Vsa g` s@ o PMM wnLLnc: R. LYMnN.

SGPPLY TnNK BY l T'ORNEY Filed March 27, 1943 Jan. 17, 1950 w. R. LYMAN OIL BURNER APPARATUS INCLUDING AN AUTOMATIC DELAY Acfuou FUEL vALvE sa m4 1? los loo 94 9s 9s` 3B ns so Il: los/Ta WALLACE R. LYMRN.

ORNEY E* E W Patented Jan. 17, 1950 UNITED STATE S PATENT OFFICE OIL BURNER APPARATUS, INCLUDING AN AUTOMATIC DELAY ACTIN FUEL VALVE Vania Application March 27, 1943, Serial No. 480,725

I Claims.

My invention relates to oil burning apparatus and. more particularly, to controlling the liow of combustion air and fuel oil into the combustion chamber of such apparatus.

Infconventional oil burners, gear pumps are usually employed for delivering fuel oil to the combustion chamber. This pump and the blower, which supplies the combustion air. are driven by a single motor which is energized by a manually or thermostatically operated switch. Due to the positive displacement of the oli by the quick action of the gear pump, and due to the compressibility and slipping of the air, the gear pump overcomes the resistance to which a conventional cut-oi! valve and pressure regulator may be set, and the fuel oil reaches the comhustion chamber, well before the supply of combustion air reaches its rated or normal flow. This creates a slightly explosive mixture such that ignition under these conditions often shakes the boiler or iurnace in which the burner is installed and in turn may shake the house. While this condition is usually not serious enough to be dangerous. it is very annoying and the present practice of oil burner service men in handling serious complaints involves the sacriiiclng of economy by making an excessive burner air or draft adjustment in order to correct such starting conditions. it is also pointed out that the initial oil flame due to this limited air supply on starting is smoky and unnecessary soot accumulation on the heating surface will naturally result.

lt is, therefore, one object of my invention to provide an improved oil burner.

A further object of my invention is to produce an oil burner which will be :tree from the starting conditions referred to.

il iurther object of this invention is to produce an improved control mechanism for retarding the delivery of oil to the point of ignition until an adecuate supply of combustion air has started to flow into the combustion chamber.

A stili further object of my invention is to produce an improved control of the type set forth which is completely automatic and positive in its operation.

A still further object of my invention is to produce a control of the type set forth which is of a simple, dependable and inexpensive construction.

A still further object is to produce a control of the type set forth which is compact so that it may be easily added to conventional burners without materially increasing the overall dimensions or altering the general design thereof.

A still further object of my invention is to produce a control oi the type set forth which can be (Cl. 15S-36.3)

2 easily applied to oil burning apparatus already built and in use as well as to apparatus to be built in the future.

Accordingly, my invention provides movable means for receiving or making room for the initial supply of oil delivered by the pump when the burner is started, to delay the development ofthe pressure which opens the cut-od valve, said means being automatically returned to its original position when the burner is turned oil'.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part ol' this application, in which:

Fig. 1 is a vertical cross-sectional View ol an oil burner embodying my invention;

Fig. 2 is an enlarged sectional view on line lI-II of Fig. l; and,

Figs. 3, 4, and 5 are views similar to Fig. h showing modied forms of construction.

Figa. l and 2 Referring to the drawings, and more particularly to Fig. 1, there is shown a conventional oil burner including a casing It having a blast tube i2. In the casing i c are mounted the usual blower I4, motor I8, gear pump I8, and conventional combined cut-oli and pressure regulating valve 20. The blower I4 and pump I8 are driven by the motor i t in any approved manner. In the blast tube i2 are the usual oil nomic 22 and ignition eiements 24. The ignition elements 24 are connected to a transformer 26 by wires 2t and the nozzle 22 is connected to the pressure regulating valve 2d by a tube lil. The discharge side of the gear pump i8 is connected by a passage 3| to a compartment 32, at one end of the regulating valve 2li, and the inlet side of the pump is connected by a passage 33 to a compartment 34 at the other end of the pressure regulating valve 2D. The inlet side of the pump is also connected by a pipe 35 to a supply tank (not shown).

The combined cut-oil and pressure regulatlng valve 20 includes a piston 3i biased to the right by a spring 3B, and a needle valve 40 biased in the opposite direction by a spring 42.. One end 44 oi the needle valve 40 is adapted tc close a passage 45 which leads into the pipe n. and the other end 41 of the needle valve 40 is adapted to close a passage 48 formed in the piston li.V

by the spring 42 is limited by abutment of the collar Sil against the nut i.

With the conventional structure thus far described, no oil ows through the tube 3l! and nozzle 22 until enough pressure is developed against piston 36 in the compartment 32 to move the piston to the left against the action of the spring 38 and' out of contact with the end dl of the needle valve Ml. The spring l2 now moves the needle valve Il@ away from its seat to open the passage But, due to the positive displacement of the oil, and the rapid action of the gear pump, the pressure necessary to displace the piston 35 is developed, and oil is discharged through the nozzle 22, Well before the combustion air delivered by the blower Il reaches its rated or normal flow through the blast tube i2.

In order to eliminate this condition and prevent explosive mixtures and improper combustion resulting from the initially inadequate supply of combustion air when the burner is started, I incorporate in the oil supply system an oil discharge delaying mechanism 52, one form of which is shown in Fig. 2. This mechanism comprises a cylinder 54, one end of which is connected by a pipe 56 to the discharge side of the pump I8, and the other end of which is connected by a pipe 58 to the pipe 35 or some other part communicating with the supply tank or the inlet side of the pump.

Within the cylinder 54 there is disposed a piston ED which is exposed to oil pressure in the pipe 56. A spring 62 biases the piston to the right,

the purpose of this spring being to move thed piston to the right-handend oi the cylinder when the oil pump I8 is not operating. rIhe force of the spring 62, which need be great enough only to move the piston to the right, is always such that the oil pressure developed by the pump in normal operation overcomes the force of the spring :and moves the piston E@ to the left in Fig. 2. The stroke and bore of the piston, that is, the piston displacement, is such that a certain amount of time, such as, 1 or 2 seconds, more or less, Will be required for the oil displaced by the pump to move the piston t@ from one end of the cylinder to the abutment iid.

Operation-Figs. 1 and 2 When the oil burner starts, oil is immediately displaced by the pump it. Due. to the lower resistance of the spring t2, the oil displaced by the pump I3 rst displaces the piston Gil against the force of the spring 62, and the pressure in the compartment 32 is not enough to move the piston 36. In other words, the piston @t is movable under a pressure of the oil which is less than the predetermined oil pressure at which the piston 36 is movable to open the valve 45t.

When the piston t@ has been moved until it abuts against the stop lili, no more oil can be received by the cylinder 513 and the oil displaced by the pump now acts against the piston 36 to move it to the left. The spring it causes the needle valve to follow the piston 3S until the collar 50 strikes the nut 5l, thereby opening the passage 45. Oil now ows through the passage and the pipe 3l! to the nozzle 22.

The time consumed in moving the piston G0 through its travel should be sumcient,to permit the combustion air to reach substantially its normal now so that, when fuel oil begins to iiow through the nozzle 22, the air supply will be adequate to produce proper soot-free combustion.

Since the pump I8 delivers more oil to the compartment 82 than is required to maintain the desired pressure therein, which may be, for example, 100 pounds per square inch, the excess pressure ol the oil will further move the piston 8S away from the end 41 of the needle valve 40 to open the passage 48. This permits the escape of enough oil to maintain the pressure in the compartment 32 at about 100 pounds per square inch. In this way, the pressure in the compartment is maintained substantially constant at the desired value. This value may be adjusted by turning the adjusting -screw 65, the structure and operation of which are Well understood in the art and hence need not be further explained here.

When the burner is turned oit, pressure in the compartment drops and the spring 38 actuates the piston 38 and the needle valve 40 to the right in Fig. L to shut 0E the flow of oil to the nozzle 22. In the absence of pressure, the spring 82 moves the piston 6G back to its starting position -at the right-hand end of the cylinder 54, until the piston 60 abuts against the inner face of the nut 61. The parts are now in the position shown in Fig. 2 and the burner is ready to begin another cycle. The oil displaced by the return movement o! the piston-60 slowly leaks past the gears of the pump I8 or through the relief slot 48 in the end 41 ofthe needle valve 48.

' Fig.' 3

In Fig. 3, I show a modified form of the construction shown in Fig. 2, in which the pipe 56, cylinder 54 and pipe 58 are omitted and replaced by another oil discharge delay device 10. The discharge delay device 10 comprises a casing formed of a cup-shaped member 12 and a cornplementary closure member 14. The

members

12 and 14 denne a chamber 16 in which is disposed a diaphragm 18 clamped between two discs 80 and biased by a spring 82. In the member 14. is formed a' recess 84 for accommodating the discs 88 and limiting the movement of the diaphragm4 18. The closure member 14 is preferably provided With a test opening 88 normally closed by a screw 90. The casing 10 is secured to and communicates with the high pressure side of the pump I8 through a nipple or coupling 82.

Operation-Jig.l 3

When theburner is turned on, the initial supply of oil delivered by the pump I8, moves the diaphragm 18 against the action of the spring 82, which is weaker than the spring 38. 'I'he movement of the diaphragm 18 from the solid to the broken line position provides room for accommodating the initial discharge of oil, thus delaying development of pressure in the compartment 32 sumcient to overcome the spring 38. It will be noted that as the diaphragm 18 is moved across the chamber 16, the air in said chamber is compressed, thus forming a resilient cushion for said diaphragm. This resilient cushion assists the bodiment is otherwise the spring 82 in returning the diaphragm to its normal position when the burner is turned oft. If it is desired to test the apparatus for leakage, the

screw is removed and the burner is turned on. Except as pointed out, the operation of this emsame as that described in connectionwith Fig. 2. I

Figs. 4 and 5 In Figs. 4 and 5, I show two embodiments in which the oil discharge delay device, instead of being in the nature of a separate unit connected to the pump, as shown in Figs. 2- and 3; is incorporated in a. combined cut-ot! and pressure regulating valve, such as that illustrated in Fig. 1 and commonly used in oil burners.

The embodiment shown in Fig. 4 includes a piston I4, a tube B and a collar 98 carried by one end of the tube 88. The piston 94 is slidable with respect to the casing 'of the pressure regulating and cut-oi! valve casing and the tube 96 and collar I8 are slidable within and relative to the piston I4. The piston 84 and collar 98 are biased in op posite directions by a spring |00 which is weaker than the spring 38 which biases the collar 98 and tube 98. and indirectly, the piston 94 to the right in Fig. 4. The other end of the tube 96 bears against and is closed by the end 41 of the needle valve 40. The interior of the tube 96 constitutes a passage corresponding to the passage 48 of Fig. 2. 'I'he piston 84 is provided with a cut-out |02 to reduce friction and facilitate its movement. The collar 8l is provided with an oil relief slot |04 and. is adapted to be engaged by a shoulder |06 in the piston 04, when the piston 94 is moved to the left in Fig. 4. In its extreme righthand position, the piston t4 abuts against a shoulder 95. Except as pointed out, the rest of the structure of the pressure regulating and cut-ofi valve is the same as that described in connection with Fig. 2.

@paranoia-Fig. 4

When the oil burner is started, the initial discharge of oil into the compartment 32 merely moves the piston 94 against the force of the spring i00 and. thus makes room for accommodating the initial supply of oil discharged by the pump ld. Since the compartment 02 is in the path of the oil flowing from the gear pump i8 to the burner nozzie 't2 through the passage 3|, the compartment 32, the passage 45 and the tube 30, as will be seen in Fig. i, it is apparent that there is no constriction between such flow path and the compartment I2. The compartment 32 may, theretore, be said to be in unconstricted communication with said flow path. Such unconstricted communication permits the oil to be received in the compartment 3.2 during the initial period of operation of the pump as rapidly as it is discharged from the passage 3| of such path. The force of the spring 38 being greater than that of the spring |00, even when the latter is compressed,

the tube 86 is not moved, and the needle valve 40 remains in position to close the passage 45. When, under increased pressure, the piston 94 moves further, the shoulder |06 engages the collar 98, and the collar 90 and tube 9E are moved to the left against the force of the spring 38 to disengage the tube 06 from the end 4l of the needle valve 40. The relief slot |04 prevents undue accumulation of oil Within the piston 94. Again, except as pointed out, the apparatus operates in ine manner previously described in connection with Figs. 2 and 3.

The embodiment shown in Fig. 5 includes a relatively short piston |08 corresponding to the piston 94 and a separate stop ||0 corresponding to the collar 98. The piston |03 and stop ||0 slide within a ilxed sleeve |l2. The stop ||0 is carried by one end of a stem H3, the other end of which slides through an opening in the head of the piston |08. A spring ||4 biases the piston |08 and stop |||J in opposite directions while the spring 30 biases the stop ||0, stem ||3 and, indirectly, the piston |08 to the right in Fig. 5. The stop I i0 is provided with a. relief groove I 5 which performs the same function as the relief groove |04 in Fig. 4. The piston |08 is provided with a longitudinal relief groove i I8 which terminates in an annular relief groove ||8 formed in the outer surface of the piston |08. A portion of the groove ||8 is adapted to register with a relief groove |20 formed `in the sleeve ||2 when the piston |08 is moved suiilciently to the left in Fig. 5 to displace the collar ||0 and open the valve |22. The annular groove |8 is provided in order to eliminate the necessity of aligning the groove ||8 with the groove |20. In this construction, the needle valve and the port 48 are omitted and the passage is closed by a valve head |22 carried by the other end of the stem ||3 and coacting with a valve seat |24. The valve head |22 also serves as a stop for the piston |08 when the latter is in its extreme right-hand position.

Fig. 5-Operation The initial discharge of oil into the compartment 32 moves the piston |08 against the action of the spring until the piston abuts against the collar H0. During this time, the valve i22, under action oi' the spring 38, keeps the passage 45 closed and no oil flows through the pipe 30 to the burner nozzle. As the pump continues to deliver oil to the now enlarged compartment 32, the piston |88 moves the collar ||0 to the left, thus moving the valve |22 away from its seat to open the passage 45. Further increase inl pres sure of the oil in the compartment 32 moves the piston |08 and collar ||0 still further` to the left and brings a portion of the groove i8 into registration with the relief groove |20. This permits some of `the oil in the compartment 32 to escape through the 4relief outlet 33 to maintain the pressure in the compartment 32 substantially constant, in a manner similar to that described in connection with Figs. l and 2.

It will thus be seen that the action of my oil discharge delay mechanism creates a suilcient lag `or delay in the arrival oi the fuel oil at the point of combustion, until the motor energizing the fuel pump and the blower has come up to speed and the combustion air delivered to the combustion chamber has reached its rated fiow, or a satisfac-n tory adequate volume.

My invention is especially useful for delaying the discharge of oil in a construction in which the blower and the pump are driven by the same motor as distinguished from apparatus using separate motors for driving the blower and the pump, with the motor driving the pump being 'energized after the energization of the motor driving the blower.

It will further be seen that I have devised a simple, inexpensive, and compact oil discharge delay mechanism which can be added to oil burners already installed and in use, as shown :in Fig. 2, and which can be incorporated in the standard pressureregulator forming part of conventional oil burners without greatly modifying its standard construction and design. It will also be seen that the oil discharge delay described can be incorporated in a conventional pressure regulating and cut-off valve without materially increasing its overall dimension or the weight thereof.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited. but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specically set forth in the appended claims.

of oil through said nozzle, valve control and discharge delay mechanism comprising spring-bi.

ased means controlling said valve and normally assuming a first position in 4which said valve is closed, means responsive to oil pressure from said pump of a predetermined value for moving said spring-biased means to a second position in which said valve is open, and pressure-responsive means subjected to the pressure of the oil and movable through a limited range, independently of said spring-biased means, under pressure less than the said predetermined pressure value, the movement of said last-mentioned pressure-responsive means providing room for accommodating the oil initially discharged by said pump to delay the opening of said valve until the air delivered by said blower to said combustion chamber has reached substantially its normal flow.

2. The structure recited in claim 1 together with means for returning said pressure-responsive means to its initial position when the flow of' l oil is cut oif.

3. In an oil burner including a blower for delivering combustion air to the combustion chamber of said burner, a nozzle for delivering fuel oil to said combustion chamber, a positive displacement pump for delivering oil under pressure, means defining a flow path for said oil from the discharge side of said pump to said nozzle, a single motor for driving said blower` and said pump, and a valve controlling the flow of oil through said nozzle, valve control and discharge delay mechanism comprising spring-biased means adapted to be subjected to the pressure of said loil for controlling said valve and normally assuming a first position in which said valve is closed, said spring-biased means being movable by the oil pressure, when said oil pressure has reached a predetermined value, to a second position in which said valve is open, and means for delaying the opening of said valve to permitcombustion air delivered to said combustion chamber to reach substantially its normal oW, before any oil is discharged through said nozzle to said combustion chamber, including a compartment having unconstricted communication with said flow path, a plunger in said compartment, means biasing said plunger in a direction to oppose the ading said casing through said mission of oil into said compartment, said biasing means being of such strength as to yield under a pressure less than said predetermined pressure value to open said compartment for receiving the initial amount of oil delivered by said pump, thereby delaying the development of said predetermined pressure value against said pressureresponsive means.

4. In an oil burner including a blower for delivering combustion air t0 the combustion chamber of' said burner, a nozzle for discharging oil to said combustion chamber, a positive displacement pump for delivering oil under pressure to said nozzle, a single motor actuating said pump and said blower, and a valve for controlling the fiow of oil from said pump to said nozzle, valve control and discharge delay mechanism comprising a spring-biased element normally engaging and urging said valve to closing position to pre- 8 vent the flow of oil through said nomle, said spring-biased element being movable by oil pressure from said pump of a predetermined value in valve opening direction, and means for delaying the movement of said spring-biased element and the opening of said valve, to delay the flow of oil through said nozzle until the air delivered by said blower has reached its normal now, including a plunger subjected to the pressure of oil delivered by said pump and movable by oil pressure less than said through a limited predetermined pressure value range independently of said spring-biased element, the movement oi' said plunger through said limited range providing room for receiving the initial amount of oil delivered by said pump and thus delaying the development of said predetermined pressure value and the opening oi' said valve, said plunger being movable beyond said limited range when the oil pressure has reached said predetermined value to engage said spring-biased element and actuate the same in valve opening direction.

5. A delayed opening flow control devicecomprising a casing having a fluid inlet and a uid outlet, a valve for controlling flow of fluid from said inlet to said outlet, a spring biasing said valve to open position, a spring-biased member normally engaging and maintaining said valve in closed position against the force of said spring, a plunger subjected t0 the pressure of fluid enterinlet, and a spring biasing said plunger against the pressure of said fluid with a predetermined force value, said plunger being movable through a limited range, and independently of said spring-biased member, by the pressure of said fluid, when said pressure exceeds said predetermined value, to provide room for a portion of said iiuid, said plunger being further movable, upon further increase vin fluid pressure, to contact and move said spring-biased member in valve opening direction, to permit opening of said valve by said first-mentioned spring.

6. A delayed opening ow control device comprising a casing having a fluid inlet and a fluid outlet, a valve for controlling flow of fluid from said inlet to said outlet, a spring-biased member normally engaging and maintaining said valve in closed position, a plunger subjected to the pressure of fluid entering said casing through said inlet, a spring biasing said plunger against the pressure of said fluid with a predetermined force value, said plunger being movable through a limited range, and independently of said springbiased member, by the pressure of said fluid, when said pressure exceeds said predetermined value, t0 provide room for a portion of said uid, said plunger being further movable, upon further increase in fluid pressure, to contact and move said spring-biased member in a valve opening direction, and a by-pass operative in response to further movement of said plunger, after said valve has opened, for by-passing a portion of the fluid flowing from said inlet to said outlet.

7. A delayed opening ow control device comprising a casing having a fluid inlet and a fluid outlet, a valve for controlling flow of fluid from said inlet to said outlet, -a spring-biased member normally engaging and maintaining said valve in closed position, a plunger subjected to the pressure of fluid entering said casing through said inlet, a spring biasing said plunger against the pressure of said fluid with a predetermined force, said plunger being movable through a limited range, and independently of said spring-biased member, by the pressure of said duid, when said pressure exceeds a. predetermined value, to provide room for a. portion of said iiuid, said springbiased member being movable by the pressure of said duid when it reaches a, greater predetermined value to permit opening of said valve after said plunger has moved through its limited range, and a by-pass operative in response to further movement of said spring-biased member after said valve has opened, for by-passng a. portion of the fluid flowing from said inlet to said outlet.

WALLACE R. LYMAN.

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

UNITED STATES PATENTS Number Name Date 841,791 Lemp Jan. 22, 1907 1,128,977 Taylor Feb. 9. 1915 Number 10 Name Date Pfau Oct. 26, 191.5'4 Fulton Jan. 25. 1916 Winslow Aug. 10, 1920 Harris Apr. 26, 1921 Meyers Feb. 5, 1924 McTarnahan Sept. 8, 1925 Webber Jan. 3, 1928 Williams Aug. 4, 1931 Dorman May 31, 1932 Ballard June 28. 1932 Nightingale et al. Aug. 30, 1932 Klotzman Feb. 1.4, 1933 Czarnecki Aug. d, 1936 Murphy Aug. 111, 1936 Fellows et ai June 7, 1938 Murphy Sept. 20, 1941. Aldrich Nov. 25, 1941 Scott June 16, 1942 Klimpel July 28, 1942 Rockwell Mar. 20, 1945