US2397987A

US2397987A - Liquid fuel burner system

Info

Publication number: US2397987A
Application number: US428391A
Authority: US
Inventors: Senninger Earl Joseph
Original assignee: SANMYER CORP
Current assignee: SANMYER Corp
Priority date: 1942-01-27
Filing date: 1942-01-27
Publication date: 1946-04-09
Anticipated expiration: 1963-04-09

Description

April 9, 1946 E. '.1. sENNlNGER LIQUID FUEL BURNER SYSTEM 5 'sheets-sheet 1 Filed Jan. 27, 1942 INVENTOR.

Hrm/5.

April 9, l946- E.Y J. sENNlNGER 2,397,987

L-IQUID FUEL BURNER SYSTEM April 9, 1946. E. J. SENNINGER 2,397,987

LIQUID FUEL BURNER SYSTEM April 9, 1946.

Filed Jan. 27, 1942 E. J. SENNINGER LIQUID FUEL BURNER SYSTEM 5 Sheets-Sheet 4 Hrryg,

April 9, 1946 E. J. SENNINGER LIQUID FUEL BURNER SYSTEM y Filed Jan, 27, 1942 5 sheets-sheet 5 Patented Apr. la, 194s orties LIQUID FUEL BURNER enormi.

Chicago, lli., assigner to a corporation oi Illinois Application Jennery et, isis, sel-iai no.' esi-ssi Earl Joseph Senninger, Sanmyer Corporation,

as c (menswear on the lines o o, sofia g This invention relates to liquid fuel burner systems and has for its principal object to maire the burner come on with a very small lire when it starts. built up to the size required by the de1 mand and modulated between high fire and low re -in accord with the varying demand for heat.

The preferred improvement of the invention specifically disclosed in this application is defsigned especially for use with the scheme forming the subject matter of my companion application, Serial Number 428,390, iiled concurrent- 1y! of variable capacity subject to a suilicient pressure of primary or atomizing air and the delivery of secondary air can be varied, by opening and closing the inlet to the ian or blower.

Generally speaking, the object of this invention is attained by making the pressure of primary or atomizing air act with appropriate delay at starting to increase the delivery of fuel and air to the v burner and afterwards making the temperature or pressure in the space to be controlled vary the etlect of the primary air pressure on the delivery of fuel and air in accord with the varying demand for heat.

in which fuel is delivered by a metering pump the chamber i-i i, iii-uit, respectively, of Fig. 7.

But these specific illustrations and theicorre spending description are used orthe purpose oi disclosure only and are not intended to impose unnecessary limitations on the claims, or confine the patented invention to a particular use.

General description In the diagram (Fig. 1) a main housing I0 provides a tank or reservoir Il, for lubricating oil, a chamber it for primary or atomizing air above the oil tank, two air filters or cleaners and oil separators I3 and I4, and a secondary ran or blower casing I5, communicating'with a horizonr tally directed draft tube l`6, passing out through l2 and within which are the following parts, which have been displaced and shown below in the diagram;

The primary air line Il, supplying the nozzle i8, the oil line I9 with itsassociated heater 2t, also delivering oil to the nozzle I8, and the electrodes 2i associated with the nozzle for igniting the mixture `of oil and air when the burner is started.

Furtherobjects and advantages or the invention will appear as the disclosure proceeds and the description is read in connection with the accompanying drawings, in which Fig. 1 is a diagram of the system with the parts displaced in such a way as whole in one drawing;

Fig. 2 is a side elevation vof a commercial burner unit embodying the invention with a portion oi the modulating motor broken away;

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 2;

Fig. 3a is a perspective view-o! a disk forming part of the means for adjusting the capacity of the oil pump;

Fig. 3b is a perspective view of a crank cooperating with the disk shown in Fig. 3a;

Fig. 3c is a perspective view of the end portion of the oil pumpcasing;

Fig. 4 is a vertical section throughthe commercial oil burner unit shown in Fig. approximately along the axis of the draft tube;

Fig. 5 is an enlarged longitudinal section of the burner nozzle and associated parts;

Fig. 6 is a transverse section on the line 8 6 of Fig. 5:

Fig. 7 is an enlarged longitudinal on the line 1-1 ofFig. 2, and

Figs. 8, 9, 10, 11, 12, are sectional views taken section taken to reveal an organic 2, taken The main housing also forms a support for an electric motor 22 which drives the secondary air fan or blower 23, a primary or atomizing air pump 24 and an oil pump 25, here shown as arrangedA in alignment crosswise to the main housing.

The secondary air fan or blower 23 takes air through the slotted side wall 23 of the fan casing i6 under control of the rotary shutter `21 and delivers it through the draft tube I6 around the mixture,` of oil and air discharged from the orice 230i the nozzle I8. The volume is varied by adjusting the rotary shutter 2l.

The primaryl or atomizing air pump 24 takes air in at 29 and delivers it through a pipe 30 into the upper portion of the main housing through the filter I3, which is charged with bronze wool,

Vinto the chamber I2 through which it passes over the supply of lubricating oil 3| and up through the iilter I4 out through the pipe 32 leading tov the airline i'i. In fact, that air line,.the

pipes

30 and 32 yand the chamber I2, may be considered as forming a single air line with a storage or pressure chamber in an intermediate position which insures an even dow to the nozzle and forms pressure for several other purposes.

The lubricating oil tank II is connected near the bottom by a pipe 33 with the pump 24 and by reason of the air pressure within the chamber I2 oil from the supply 3i in the tank Il is continuously delivered to the air pump. as a result. this 2' pump delivers a mixture of air and oil or air and oil foam to the pipe 30 whereby the bronze wool In the iilter I3 is'made to serve as an oil separator and an air cleaner and the lubricating oil collected there drops down over the outside of the draft tube I and returns to the tank vI I. The lter I3 is separated from the illter I4 by apartition 34,

and the air compressed in the chamber I2 passes up through a second mass of bronze wool in the filter I4 before entering the pipe.32.

In practice, the apparatus is so designed that a pressure from five pounds to twelve pounds,

.for example, may be built up and maintained in the chamber I2. The pressure in the primary or atomizing'air system is regulated by a bypass 35 connected across the inlet and outlet of pump 24 and controlled by an adjustable valve l36. In

this diagram the bypass is shown Aas external piping, but in practice is worked out through the body or casing of the pump. l

The oil pump 25 is preferablybuilt formetering purposes only and should not be used to draw oil from the storage tank.- Where gravity feed cannot be used, auxiliary pumping equipment 31 movable in the cylinder 40 serves to connect the line 38 with the line 4I or with the bypass 42, as

occasion may require. The piston is associated with an air motor, here shown as a Sylphon bellows 44 located in the primary air chamber I2 and subject to the pressure in the chamber. As a result of thisarrangement, oil from the pump.25 is bypassed back to the supply line until there is suiiicient pressure in the air chamber I2 Electric power for the liquid fuel burner system described maybe taken from the house line 45 l operation.

andthe apparatus shown in the diagram will be understood from the following description of the When the room thermostatror boiler control 46 calls for heat Minneapolis-Honeywell R 117 relay` 41 will be energized and close an electric circuit to the delayed action switch 43 allowing current to ilow to the oil heater 20 and the ignition transformer 49. After a delayed action, for

example, twenty-five seconds, switch 48 will close the circuit to motor 22, which will start the sec ondary air fan or blower 23, the primary or atomizing air pump 24 and the oil' pump 25. While theA pump 24 is building up the necessary pressure in the chamber I2, oil from the pump is recir culated through the bypass, and the heater v2Il is conditioning the.ol l in the pipe I9 and warming up the associated parts of the burner. When the pressure in vchamber, I2 reaches the selected amount the Sylphon 44 will be compressed and the pistonvalve 43 will cut out the bypass 42 and connect up the oil line leading to the nozzle I8. As the'mixture of air and atomized heated oil is discharged from the orifice 2l of the nozzle, sparks from the electrodes 2| furtheried bythe supply of secondary air deto insure delivery of a proper amount of primary or atomizing air 'to the nozzle I8, when the pressure in the chamber I 2 will overcome the Sylphon 44 and shift the piston valve to a position in which it connectsthe pipe 39 with the pipe 4I and that, with the pipe I 9, becomes one oil supply line from the pump to the nozzle. When, for any reason, the air pressure in the chamber I2 drops below that for which the device is designed and adjusted, the piston valve will shift to the right, cut

oil the supply of oil to the burner and connect the pump 25 with the bypass 42.

By making the presence of a. considerable amount of lubricating oil in the primary air pump 24 necessary to seal it and give it the required capacity, it becomes impossible to run the p ump long with insuilcient lubrication for, as soon as the pressure in the chamber I2 drops below that required, thesupply of oil is cut olf and the control of any one of the customary forms will put the apparatus on safety and shut the burner down entirely. The presence ofthe 'lubricating` oil in the air pump 24 in such quantity as to form a foam makes it possible to provide a very eilicient filter with the bronze wool in the filter I3, which also serves as an oil separator and delivers the excess of oil back to the supply in the tank I I.

Any one of the many types of oil burner controls may be used with this system and none will be described in the interest of brevity. It will be sulcient vto refer to Oil Heating HandV Book," by Hans Kunitz, second edition, and "The Starvbuck Oil Burner Manual, 1941.

- its pressure against the piston 5I.

- ance of livered by the fan or blower 23-through the draft tube is. After a short interval relay u win shut oiilthe current to the ignition transformer 4 9. 'I 'he resistance of the heater element 20 increases with the rise4 in temperature and the wattage drops to the selected limit for the particular design.

` -Mention of Minneapolis-Honeywell R 117 relay is merely by way of example. Many other controls can be used and-some other controls must be used when the lire adjusting apparatus, later described, is associated with the burner.

' Adjusting the fire According to this invention, the operation of the apparatus described is modied to make theV burner come on with a very small fire built up tothe size required by the demand and thereafter vary with the varying demand. One embodiment of means to that end includes an airmotor comprising a cylindern50, equipped with a piston 5I whose piston rod 52 runs through `the guide 53 and has one arm 54 connected by a, link 55 with the rotating shutter 2I`oiI the secondary air fan or blower and another arm 56 connected by a link 57 with a lever 58 on the oil pump 25 by which its capacity may be adjusted and enlarged as the shutter 21 is opened to increase theV delivery of secondary air by the fan or blower 23.

'Ihe piston 5I is normally urged to the position shown by a spring 59 and its limit in that direction is determined by a low fire stop 60, its limit in the other direction being determined by a high re vstop SI, both adjustable on the piston rod 52 and made fast by set screws or the like.

In order t`o move the piston against the resistspring 59, air from the chamber I 2 is conducted by a pipe 62 and delivered to a head chamber 6 3 in theair end of the cylinder 50 from which it passes by a port 64 into the cylinder and exerts The length of needle 65 will time interval the pipe 62 and the adjustment of a make the flow of airinvolve the desired for response to change in demand. and

the supply of air and oil will be increased or decreased in relation to the pressure permitted to build up against the piston head, this function,

ignite it and the flame is however. being limited by the adjustment o! low fire stop B and high fire stop Bl. In some designs, the length of the pipe 82 will have a-negllgible effect and the control will be effected chiefly by adjusting the needle valve t5.

with this arrangement the burner will, startl check valve Il, back to the chamber l2 and be discharged through the nozzle.

However, it is preferable to add a modulating control, one embodiment of which includes a pneumatic temperature or pressure device 68, connected with the cylinder 5B by a pipe 89, ending in a nozzle 1.8, when the temperature or pressure of the device il, or the space to which it is subject. reaches the point at which it is set. the arm ll will uncover the oriilce l0, allowing some air pressure to such a point that it will not overcome the force of the sprint Il and furthermore, the needle valve 85 ofthe modulating motor prevents the pressure which is built up by the primary air pump prior lto ignition from throwing the modv ulating motor oi! of low fire position. However,

to escape, thus lowering the pressure in the cylinder 50 and allowing the piston to move toward the air end of the cylinder under the action of the spring 59, thus reducing the supply of secondary air and oil. The piston will adjust itself'to-some point between high hre and low fire positions, depending on the demand indicated by the arm ll. If the temperature or pressure at the device 68 should drop or increase, the port 10 will be opened or closed correspondingly and, hence, the re will be adjusted to correspond with the demand.

'Ihe device B8 may be any pneumatic control that will open a port on an increase of temperature or pressure and bleed. the air from the line 69 to the atmosphere, or close the port on a decrease of temperature or pressure, such, for example, as Minneapolis-Honeywell L-092D. These devices are available in a number of scale ranges and may be used as a warm air control by mounting in the air stream, as an immersion aquastat by inserting it in the liquid to be controlled or as the steam pressure control, by mounting it in the boiler water just below the water line. The boiler water temperature changes with the steam pressure in accordance with familiar steam tables. As these devices and their applications are familiar, specific disclosure is omitted in the interest of brevity.

To summarize the sequence of operation which takes place whenever the burner is started:

First, the thermostat 48 closes the circuit through the relay 4l which in turn causes current to flow through the heating element 20 and to the ignition transformer 49. After a given time interval, for example seconds, the circuit through the electric motor 22 is cclosed which starts the primary air pump 24, the secondary air blower IE and the oil pump 25. In approximately two or three seconds after the air pump 24 is placed in operation, the pressure in the chamber I2 is suiiicient to open the fuel valve to the nozzle and the fuel in the oil line immediately adjacent to the nozzle has, in the meantime, been heated to a temperature which is sufiicient to bring about quick ignition when atomized at the nozzle and subjected to the ignition spark. When the fuel valve is opened, causing oil to ow to the nozzle, the modulating motor is at low fire position, as shown in Fig. 1, because the escape of primary air through' the nozzle prior to the opening of the fuel valve holds down the primary air 'as soon as the oil begins to flow through the nozzle, a back pressure is created in the primary air line which is transmitted through the needle valve to the modulating motor and within a few seconds. say three or four seconds, after ignition has taken place, the piston 5| of the modulating motor begins to move slowly outwardly 5 thereby gradually building' up the re to the' desiredl point. This Vgradual building up of the ame from a low nre start to the size of flame called for by the burnerload demand (which maytake it or 2u seconds) is very important for proper operation of the burner because experience shows that a sudden change from low fire to high fire at the beginning oi burner operation will' cause the stack to choke and set up backl pressures which will cause smoking and otherwise interfere with proper burner operation. Ey gradually building up the llame from a low flame which is easy to ignite to a higher flame gives the hot gases a chance to clean out the stack of cold air Referring to Figs. 2, 3 and 4, it will be seen that the bottom of the main housing is formed by la base l2, having a downturned edge 'i3 and a machined ribld ony its upper face to receive and be secured tothe bottom of thegenerally rectangular wall lil, which surrounds the lubricating oil space and with the base forms the oil tank or reservoir il.

Justabove the lubricating oil tank, and at the-` right in Fig. 3, there is a hollow cylindrical projection 16, open at ll, to receive the air operated shut-oil valve for the oil supply.

Above the projection 1I is a larger hollow cylindrical projection .18, the right side of which, in Fig. 3, is formed by the slotted wall 28 and'the left side of which is formed by the partition wall 19, which is curved at 80 to form the throat orentrance to the Siroco fan or blower 23.

The draft tube- Il intersects the main housing somewhat below the mid portion, and the lower wall 8l, Fig. 4 of the draft tube, extends across the main housing above the lubricating oil tank Il and, in ehect, forms the upper portion of the chamber for primary or atomizing air.

an air pressure gauge 85. The bronze wool which really forms the :llterlnlzy and oil separating elements of the filters I 3 and Il, fills the spaces above the draft tube divided by the Wall 34 and closed by the cap 84. Removing that cap permits access for cleaning the bronze woolpwhich should be done at suitable periods by remover and man.'v

respect to the fan' or er into and through the draft tube I8.

iJust below'the fan 'casing l5 and opposite to the draft tube the main housing has an opening threaded into openings forming proper communication with the interior of the cylinder 40, which will be understood without speclc description.

The right end of the cylinder 40 in Fig. 3`is closed by a screw-headed cap I|5 which serves to compress a spring IIS against the end of the piston 43 and normally urge it to the position shown.

v collapses the Sylphon towards the right in Fig. 3, ,i

Aclosed by a. cap 86, into which the air tube. I1 isv fitted at the end opposite to that connected with l the nozzle I8. The cap also carries an approy nozzle.

priate nipple, etc., 91, for connection with the air pipe 32, thus establishing the complete air line from the primary or atomizing air pump to the At each side of the nipple 81, and slightly above, arev open insulated fittings 88 to admitl wires 89, the inner ends of which are secured to the electrodes 2| by nuts 90, (Fig. 4).

Beneath the nipple 91 the cap 86 has an opening 9| to admit the heater tube 92 which surrounds the heater 20, and the oil line I9, leading to the nozzle I8. Suitable mounting for the electrical connections and the end of the oil pipe I3 are provided by a large cast fitting 93, secured to the cap 86.- l A Forked pedestals 94 (Figs. 3 and 4) have openings`95 and 96 to receive the air pipe I1 and the heater tubeI 92 and clamps 31 to receivethe insulating tubes 98 for the electrodes 2|. Projections 99 on the clamps 98 and a leg |00 engage the inside of the draft tube and form a support for the assembly bound together by the pedestals 94. By removing the fastenings for the cap 86 this When pressure of the air in the chamber I2 lt-will move the piston to the right and compress the spring I|6. When the pressure'in the chamber I2 is relieved, thevspring I|6 willmove the parts back towards the position shown in Fig. 3 and under proper conditions will shut off the oil from the burner and connect the oil pipe 39 with the bypass 42, Fig. 1.

The shut off movement ofthe piston 43 produces a partial vacuum in the right end of the `cylinder 40, which is relieved through the passage 9 (Fig. 3) by flow from the nozzle and prevents dripping at the orifice. Thus as an incident to stopping the flow of oil to the burner when the supply of atomizing air is insufllcient, there is a slight withdrawal of oil from the nozzle that prevents dripping and a corresponding accumulation in the vcylinder which is immediately forced towards the nozzle when the airoperated shut olf valve is again shifted to permit the oil to ilow to the burner,

' The motor and secondary fan The casing of the electric motor 22 is provided with a shouldered flange II'I (Fig, 3) to nt wall assembly, called in practice the drawer assembly, l may be withdrawn as a unit from the draft tube.

The delivery end of'the draft tube is equipped with a suitable converging tting |0I (Fig. 4) to direct the secondary air against the mixture of oil and primary air` discharged from the nozzle I8. The vdetailed Aconstruction ofthe nozzle, its connection with the' primary -air pipe |1, the oil pipe I9 and its operation in use will be sufllciently clear from the enlarged section in Fig. 5, without .specific description. p The size of the orice, the spray angle and such like will vary with conditions and personal preference. l y The rectangular portion 15 of the main casing surrounding the lubricating oil space, is provided at one side in Fig.`2, with a non-breakable sight glass |02, through which the lubricating oil can be readily observed in order to maintain it at the appropriate level indicated by the line |03.

The air operated shut-01T valve for oil Referring to Fig. 3, it will be seen that the cyl'- inder 40 'of the air operated piston valve, described in-connection with the diagram, Fig, 1, has a reduced portion |04, received in and secured fast to the hollow flange |05 of a disk |06, bolted to the main casing to close the opening 11. The Sylphon bellows 44 has one end |01 soldered, or otherwise properly secured to the inner face of the'disk |06 and its opposite closed end |08, cooperates with the cartridge shaped plunger |09, the bottom of which acts directly on the stem I0 of the piston valve and the wall of which telescopes over the nipple II I on the cylinder 4|l.l

The

oil pipes

39 and 4| and the bypass pipe 42 are secured to the cylinder 40 by nipples |I2, ||3 and |I4, respectively (Fig. 3) which connections are threaded to nipples, which in turn, are

|I8 of the fan casing I5 and be secured to it by bolts. The motor shaft |I9 is tted into the hubs |20 of the secondary fan or blower. 23 which is preferably of the Siroco type.

As will be seenfrom Fig. 7, the air inlet |34 in this instance is through the disk |22 and leads to a curved inlet' passage |35 (Fig. l2) open to the inside of the pump chamber. The outlet |36 for air leads through the periphery of the disk I2| to a curved passage |31 (Fig. 1l) in communication with the pump chamber.

From this it will be apparent that rotating the shaft |25 clockwise in Fig, 11 will cause the air to enter through the inlet passage |34 and be compressed by the vanes-|3| successively and driven through the outlet into the pipe 30 leading to the main housing, Fig. 1.

The disk |22 is provided with a bushing |38 in Vwhich the shaft `|25 is journaled, and the disk asoma? A by the screw valve lu locked in place by the nu:

|42. By adjusting that valve the bypassed air can be cut off or increased in any amount to regulate the delivery of the pump to anything-within its capacity.

As heretofore stated, the Iscrew valve |4| is vadjusted to maintain some normal pressure in the chamber I2, for example a normal pressure with# in the range of tive to twelve pounds. A feature of the present form of the invention, however, is that the moving parts of primary air pump 24 are dimensioned with such liberal clearances that plentiful lubrication of the pump interior is required to cause and maintain the normal pres-l jacent surfaces of discs |2| and |22 (Fig. 7), or

between faces of rotor |24 and corresponding faces of the discs |2| and |22, or between faces of blades |3| and corresponding faces or walls of slots |30. (Fig. 11.) The provision of'such clearance requires only the ordinary skill expected inthis art. especially since the pressure created by theypump running without lubricant is not critical'. To prevent actuation of the valve piston 43, it is sufficient that the pressure from the'pump drop to any value below five pounds and a minimum pressure of only one pound will lift oil from the sump a vertical distance of over thirty inches. Thus the clearance in the working parts of the pump may be such as,.in the absence of lubricant. to drop the output pressure to any value between one and five pounds.

The oil pump Refer to Figs. 3,' 7, 8, 9 and 10. y

The casing of the oil pump 24 is formedf by a cylinder |43 integral with the hub |25 of the primary air pump and a disk-like cylinder head |44 secured by bolts. Within this cylinder |43 is a bronze rotor |45 keyed to the end of the shaft |25 by a pin |40. Adjacent to the end of the shaft |25. the rotor is provided with a transverse bore |41 in which is a double ended piston |40, the intermediate portion of which is cut away to form a notch |49, which receives an eccentric pin |50, projecting through the disk ||,which bears against the end of the rotor |45. y

Refer to Fig. 10.

From this it will appear that when the shaft G is driven, the double ended piston |48 will reciprocate back and forth and oil entering the in-. let |52 will be forced out the outlet |54.

By changing the eccentricity of the pin 50, the stroke ofthe double ended piston can be changed and thus the capacity ,orl lthe delivery of the oil pump can be varied within the limits of the `design. To accomplish this adjustment, the disk |5|, bearing the pin |50, is provided with a slot H55 (Figs. 3a, 9 and 10) which receivesl guiding pins |51, carried by the head |44. And these pins allow the disk |5I rectilinear motion crosswise t-o the axis of the shaft |25, but no rotation.

By rotating the shaft |60, the crank can be made to change the eccentricity of the pin |50 from nothing to the extreme within the range of the design and to that extreme in either direction, thus the stroke of the piston can be adjusted from neutral to maximum and the same pump may be made to act as a pressure pump or a vacuuxn pump or, in other words, the intake and exhaust sides can be reversed by simply rotating the shaft and the length of the stroke in either phase of operation can be adjusted from zero to a maximum.

In this particular liquid fuel burner system the pump will not be reversed, butit will be adjusted from varioussmall capacities to the largest within the limit of the design, and that is accomf plished in the organization shown in Fig. 1 bythe operation of thelever 58 through air pressure or the spring 50 in the cylinder 50.

Referring again to Fig. 3, it will be seen that the shutter 21 for the secondary air is rotatably mounted on the cylindrical flange |20 by whichv the pump assembly is mounted on the main housing. lI'he connection allows free rotation of the shutter without unnecessary play in opera- |54 and provided with va clamp |55 made fastk by bolts |40. This means of mounting it affords readyadjustment in connection with the stops 50 and 5|.

' For convenience in manufacture and assembly the three pumps and the motor for driving them have a common axis. 'I'he shaft for the primary air pump and theoil pump is in one piece and is connected with the shaft of the secondary air fan 23 by a yielding flexible coupling |51.

4The oil pump here disclosed has a positive displacement and, beingdouble acting, its delivery for a given adjustment and speed is constant for all practical purposes. For that reason, when it is used as a metering pump theapparatus can operate successfully in No. 5 oil.

The use of a double ended piston also has the advantage of giving the required capacity` in very small size. y

When the stroke of the piston is increased by movement of the lever 50, as described, the delivery of oil tothe nozzle is positively increased. The increased delivery of oil results automatically in increased air pressure in the air line as required for proper atomization of the increased oil flow. In a domestic oil burner adjusted for a normal pressure of five pounds in the primary chamber 2, the pressure in the chamber' has been observed to build up as high Vas ten pounds when the rate of fuel delivery is substantially increased.

One reason for the automatic rise in pressure is that the increased flow of oil at thev burner nozzleoffers increased resistance to 'air flow from the nozzle thereby tending to increase air pressure in the air line back of the nozzle.

At rst thought it wouldseem that the increase of air pressure resulting from increasing the oil ist owwould undesirably cause the modulating motor to shift the adjustment lever 58 in the direction for still greater increase in oil ow. However, the building up of primary air pressure due to the increased oil pressure does not .appreciably aiect the operation of the modulating motor because it merely causes the piston to move outwardly'a little more than it would otherwise, but this excess movement is very quickly compensated for by the reduced temperature demand at assess? through the cli line to the nozzle regardless of the viscosity of the oil, valve means for bypassing oil from the delivery side of the oil pump to the the thermostat. 1 v

and cooperating with the pin |50, to shift it inA accord with the length of the stroke or capacity of the pump required. In that instance, and in other instances, some will wish to provide a spring |68 (Figs. 8 and 9) to constantly urge the pin |50 in one direction.

The automatic increase from low fire to high lire position will not work with Minneapolis- Honeywell Relay 117 because the stack control will throw the device on safety at low fire position. In such instances the R 117 relay should be replaced by one of the many other controls as, for example, those actuated by the light of the llame instead of the stack temperature.

I claim: y

1. In an oil burner, the combination of a nozzle, fuel and primary air lines to the nozzle, a primary air pump for forcing air under pressure to the primaryj air line, a positive displacement variable capacity oil pump for supplying metered quantities of oil through the oil line to the nozzle regardless of the viscosity of the oil, valve means for bypassing oil from the delivery side of the oil pump. to the intake side thereof whenever the primary air pressure is below. a predetermined value;and means for varying the amount of oil pumped by said oil pump in response to burner load demand.v i

2. In an oil burner, the combination of a nozzle, fuel and primary air lines to the nozzle, a positive displacement'variable capacity oil pump having its discharge side connected to the fuel line, and means for Ivarying the amount of oil pumped by said pump in response to burner load demand, said means including a cylinder receiving air from the primary air system through a restriction, a piston in the cylinder connected with said pump for capacity control thereof, a spring opposing movement of the piston in response to the pressure of the primary air line, said restriction serving to delay movement of the piston in response to an increase in the pressure of the primary air line.

3. In an oil burner, the combination of a nozzle, fuel and primary air lines to the nozzle, means, including a draft tube telescoped over a portion of said lines for supplying' secondary air to the space around the nozzle, a primary air pump for forcing air under pressure to the primary air line, a positive displacement variable capacity oil pump having its discharge side connected to said line for supplying metered quantities of oil intake side thereof whenever the primary air pressure is below a predetermined value, and means for varying the amount of oil pumped'by said oil pump in response to burner load demand.

4. In an oil burner, the combination of a nozzle, fuel and primary air lines to the nozzle, means including a draft tube telescoped over a portion of said lines for supplying secondary air to the space around the nozzle, a primary air pump for forcing air under pressureto the -primary air line, a positive displacement variable capacity oil pump for supplying metered quantities of oil through the oil line to the nozzle regardless of the viscosity of the oil, and means Afor starting the. burner with a low llame and gradually increasing it to the size required by burner load demand, said means including a device for gradually increasing the amount of oil pumped to the nozzle by said oil pump.

5. In an oil burner, thevcombination of a nozzle,

vfuel and primary air lines to the nozzle, means including a draft tube telescoped over a portion of said linesfor supplying secondary air to the space around the nozzle, a primary air pump for forcing air under pressure to the primary air line, a positive displacement variable capacity oil pump. for supplying metered quantities of oil through lthe oil line to the nozzle regardless of the-viscosity of the oil, and means for starting ing a burner, means to deliver primary air to the Y burner, a secondary air passage tothe burner, means to deliver oil to said burner, and means to deliver air to said secondary air passage, the combination therewith of means to vary the Arate of oil delivery, means to vary the rate of secondary air delivery, fluid-pressure-responsive means operatively connected with both of said delivery varying means, and passage means connecting said responsive means with said primary air passage whereby said responsive means increases the rates of oil'and secondary air delivery in response to the initial establishment of operating pressure in 'said primary air passage, said passage means being restricted. to delay the response of said responsive means to said establishment of pressure.

'1. In a device of the character 'described having a burner, means to deliver primary air to the burner, a secondary air passage to the burner,

means to deliver oil to said b urner, and means to deliver air to said secondary air passage, the

ondary air delivery, iiuid pressure responsive means operatively connected with both of said delivery varying means, and passage means connecting said responsive means with said primary air passage whereby said responsive means increases the rates o f oil and secondary air delivery l in response to the initial establishment of operating pressure in said primary air passage, said asomar kpassage means being 'sumciently restricted both to delay response of said responsive meansto said establishment of pressure and to retard the rate of response thereby to cause the increase of oil and air delivery to occur gradually over a period of'tlme after a delay period.

8. In a device of the character described having av burner, means todeliver primary air to the burner, a secondary air passage to the burner, means to deliver oil to said burner, and means to deliver air to said secondary air passage, the combination therewith by means to vary the rate of oil delivery, means to vary the rate of secondary air delivery, iluid-pressure-responsive means operatively connected with both oi' said delivery varying means, passage means connecting said responsive means with said primary air air pump for supplying primary air. to the burner. means for supplying secondaryair to the burner,

' means. comprising an air. vmotor responsive to passage whereby said responsive means increases the rates of oll and secondary air delivery in re- -sponse to the initial establishment of operating pressure in said primary air passage, said passage means being restricted to delay the response of said responsive means to said establishment of pressure, a. bleeder passage from said fluid-pressure-responsive means, means to control the rate of ilow through said ybleeder passage thereby to determine the adjustment of said responsive means relative to pressurein'said primary air passage and means to operatesaid control means in' response to the demand for heat.

9. In an oil burner, the combination oi a nozzle,

fuel and primary air linesto the nozzle, a positive displacement variable capacity oil pump -having its discharge side connected to the fuel nected with said air passage for response to pres-.

sure therein, a second fluid-pressure-actuated means connectedwith said` air passage for reprimary air pressure andincluding a restriction in the primaryair line leading to the air motor for starting the burner with a low flame and then relatively gradually increasing the supply of oil and secondary air until the flame reaches its desired size. and meansfor thereafter varying size of ame with the demand for heat.

13. In a device of the class described, a burner, means for supplying air to the burner, modulating means comprising an air motor responsive to primary air pressure and including a restriction in the primary air line leading to the air motor for starting oil feed to the burner at a relatively low rate for starting the burner with a low llame, andjautomatic means responsive to such initiation of oil feed to increase the'oil feed relatively graduallyuntil the flame reaches a desired size, saidv modulating means thereafter varying the size of the llame wtih the demand for heat.

' 14. In a device of the character described, a burner, an oil passage to the burner, means to deliver air under pressure to said oil passage, means todeliver oil to said passage after delivery of air thereto is started thereby to increase the air pressure in the passage by a throttling action, said oil delivery means-including means operating initially to deliver oil to the nozzle at a minf imum rate to support a low burnerv flame, and means responsive to said increase in pressure in said passage to increase the rate of oil delivery ata relatively gradual rate thereby to increase the burner -ilsme to a desired size, and means for thereafter fully modulating the size of .the flame with the demand for heat.

15. In an oil burner, the combination of a nozzleffuel and primary' air lines to the nozzle, a

primary air pump for forcing air under pressure to the primary air line, a positive displacement variable 'capacity oil pump for supplying meteredv quantities of voil through the oil line to sponse to pressure therein, a nrst control means responsive to said first fluid pressure means effective to-inltiate oil delivery to said oil `passage at a predetermined rate for starting said burner,

determined rate to a desired operating rate.

l1. In adevlce of the character described,` a burner, an oil passage to the burner, an air passage to the burner, means to deliver oil to said oil passage, means to deliver air to said air passage, a first fluid-pressure-actuated means connected with said air passage for responseto pressure therein, a second iiuid-pressure-actuated means connected with said air passage for response to pressure therein, a first control means responsive to said first iluid pressure means effective to initiate oil deliver to said oil passage at a predetermined rate for starting said burner, a second control means responsive to said second iiuid pressure means effective to increase the rate of oil delivery gradually from said predetermined rate to a desired operating rate, and means to vary the responsiveness of said second control means in response to demand for heat.

12. In a device of the class described, a burner, an oil pump for supplying oil to the burner, an

nozzle, fuel and primary. air lines to the nozzle.

a primary air pump forforcing air under pressure to the primary air line, a positive displacement variable lcapacity oil pump. for supplying metered quantities of;` oil through the oil line to the nozzle regardless of the viscosity of the oil..

adjustable means for supplying secondary air around the nozzle, means for shutting off the flow of oil to the nozzle whenever the primary air pressure` is below a predetermined value, and

means for varying the amount of oil pumped by I saidl oil pump and the volume ofsecondary air v delivered around the nozzle in response to burner load demand.

i7. In a device of the class described, a burner, an oil pump for supplying oil to the burner, an air pump for supplying primary air to the burner, means for supplying secondary air to the burner, means comprising an air motor responsive to primary air pressure and including a restriction in the primary air line leading to the air motor for starting the burner with a low flame and then relatively graduallyincreasing the supply of oil and secondary air until the-flame reaches its desited size, means for thereafter varying the size the amount of oil delivered to the nozzle in responseto burner demand, said modulating means including an air motor responsive to primary air pressure vand operativelyconnected to said oil delivery means, adjustable means for preventing' the air motor from cutting down the supply of oil to the nozzle below a'predetermined minimum, and additionalV means for completely shutting oi the ilow of oil to the nozzle when the 'burner motor is not in operation.

19. In an oil burner, a nozzle, means for delivering oil to the nozzle, means including a burner A an air chamber with a wall thereof movable in motor for delivering primary air under pressure to said nozzle, and means for modulating the amountl of oil delivered to the nozzle in response to burner demand, said modulating means includl ing an air motor responsive to primary air presnozzle below a predetermined minimum, adjustable means limiting the volume iiow of oil to the nozzle under maximum oil burner demand, and additional means for completely shuttingfoi the ilow of oil to the nozzle when the burner motor is not in operation.

20. In an oil burner, a nozzle, means for delivering oil to the nozzle, means for delivering primary air under pressure to said nozzle, and

means for modulating the amount of oil de-v 2l. In an oil burner, a nozzle, means for delivering oil to the nozzle, means for delivering primary air under pressure to said nozzle, and means ,for modulating the amount of oil delivered to the nozzle in response to burner demand, said modu- 1 lating means including an air motor having an air chamber with a Wall thereof movable in `response to air pressure in the chamber and operatively connected to'said oil delivery means to control the g amount of oil fed to the nozzle, and means for connecting the air chamber to the primary air delivery means through a restricted orice, lsaid orifice being adjustable as to size to thereby vary the responsiveness of the air motor to rapid increases in primary air pressure.

22. In an oil burner, a nozzle, means for delivering oil to the nozzle, means for delivering primary air under pressure to said nozzle, and

means for modulating the amount of oil delivered to the nozzle in response to burner demand, said modulating means including an air motor having -response to air pressure in the chamber and operatively connected to said oil delivery vmeans to control the amount `of oil fed to the nozzle, means for connecting the air chamber to the primary air delivery means through a'restricted orice, and means for bypassing the restricted orice to obtain a quick equalization of pressure between the air chamber and the primary air delivery means whenever there is'a relatively quick drop in pressure in said latter means.

23. In an oil burner, a nozzle, meansfor fielivering oil to the nozzle, means for delivering primary air vunder pressure to said nozzle, and means for modulating the amount of oil delivered to the nozzle 1n response to burner demand, said modulating means including an air motor having an air chamber with a. wall thereof movable in response to air pressure in the chamber and operatively connected to said oil delivery means to control the amount of oil fed to the nozzle, means for connecting the air chamber to the primary air delivery means through a restricted orice, and means for bypassing the restricted orlce to 4obtain a quick equalization of pressure between the air chamber and the primary air delivery means whenever there is a relatively quick drop in pressure in said latter means, said bypass means around the oriiice including an air passage between the air chamber and the primary air delivery means and a check valve in said passage.

24. In an oil burner, a nozzle, means for delivering oil to the nozzle, means for delivering primary air under pressure to saidA nozzle, and means for modulating the amount of oil delivered to the nozzle in response to burner demand, said modulating means including an air motor having an air chamber with a wall thereof movable in response to air pressure inthe chamber and operatively connected to said oil delivery means to control the amount of oil fed to the nozzle, means for connecting the air chamber to the primary air delivery means through a restricted orice,

`and means for quickly releasing the pressure in the air .chamber whenever the burner is stopped.

25. In an oil burner, a nozzle, means including a positive displacement pump for deliveringA u oil to the nozzle at rates independent of viscosity changes, means for `deliveringI primary `air under pressure to said nozzle, means for supplying secondary air to the vicinity'of the'nozzle in a predetermined volume relationship to the rate at which oil is being fed to the nozzle, means for modulating the amount of oil delivered to the nozzle andv the secondary air delivered in vits vicinity in response to burner demand, saidv modulating means being constructed and arranged so that throughout its range of operation it substantially maintains the predetermined volume relationship between the oil and secondary air being delivered to and in the vicinity, re,- spectively, of the nozzle'.

EARL JOSEPH SENNINGER.

@eminente ci" cmfecten Patent N o 2,397,987 April 9, 1946 EARL JSEPH SENNNGER i l it is hereby certified .that error eppears in the printed specification of the wbove numbered patent requiring correction es follows: Page 7, first column, line 12, claim 8, for the Words therewith by read therewith of; and that the seid Letters Patent should he read With this correction therein that the same may conform to the record of the cese in the Patent Gee. v

Signed. and sealed this 4th dey of Junes A. D., 3.94@

iene@ LES FR i F'ifst Assistant @ammissioner of Patents.