US2586779A - Pot type burner with overhead feed - Google Patents

Description

Feb. 26, 1952 J. BREESE v POT TYPE BURNER WITH OVERHEAD FEED 4 Sheets-Sheet 1 Filed Oct. 5, 1946 mm Q NMQ mm ommmmmfiwsmgs 5 Feb. 26, 1952. J. BREESE 2,586,779

POT TYPE BURNER WITE OVERHEAD FEED Filed Oct. 5, 1946 4 Sheets-Sheet 2 jnvezzzar knees Z .5rse 4 Feb. 26, 1952 J. BREESE 2,586,779

POT TYPE BURNER WITH OVERHEAD FEED Filed Oct. 5, 1946 4 Sheets-Sheet 3 efa/irzes Z.B7"ee5 e .ifforfieys Feb. 26, 1952 J, BREESE 2,586,779

POT TYPE BURNER WITH OVERHEAD FEED Filed 001;. 5, 1946 4 Sheets-Sheet 4 7 6 fifm@wwwwomwmvoommmmmoossms \seeg 7 5 a 5 .1 i 5 7 o 714/0 0 K o o o w 2 2 w 3 o 2 .w h i 4 E. W M W o m w ,4/ I LI .M r m Z I ll! 4 2 m :1 d 5 0 7 7 M i I I w 3 3 m w m 3 \X a Patented Feb. 26, 1952 UNITED STATES PATENT OFFICE 'm'esne assignmenta'f to Breese Burners,,1nc., Santa Fe," N. Mex, a corporation 'of Delaware Application October 5, 1946, .SerlalNo, 701,539

' C aims new.

My invention relates to an improvement in liquid fuel burners and in the formation of; a dry gas from a vaporized liquid fuel.

One purpose is to provide animproved liquid:

fuel burner.

Another purpose is to provide an improved means of and method for forming a dry gas which may be used, for example, in combustion.

Another purpose is to provide an improved liquid fuel vaporizing means for a burner.

Another purpose is to provide a liquid fuel burner and control unit.

Other purposes will appear from time to time in the course of the specification. t

The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a vertical axial section with parts in side elevation;

Figure 2 is a plan view of the control, withpar-t-s broken away and parts in section;

Figure 3 is a longitudinal section on the line 3--3 of Figure 2;

Figure 4 is a section on the line 4-4 of Fig,- ure 3;

Figure 5 is a partial section on an enlarged scale on the line 55 of Figure 3;

Figure 8 is a diagrammatic view of a generated cam slot; and

Figure '7 is a partial view, similar to Figure. 1, illustrating a variation.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, and first to Figure 1, it illustrates a hydroxylating type pot, I, having a horizontally axised generally cylindrical side wall 2 and a closed end 3. The pot-ma'y have the usual primary air inlets 4, spaced circumferentially about the pot and at various distances from the ends of the pot. Any suitable'arran'ge ment of secondary air inlets 5 may be used. I illustrate, however, a single row of tilted inlets which are both larger and more closely spaced than the primary air inlets t. The pot is shown as having an open end surrounded by an outwardly extending flange 6. The potis mounted within the coaxial outer housing I. "Its otherwise open end is partly closed by the centrally apertured flame ring 8. The end wall or ring 9 of the housing l constitutes one side of a blower housing or casing and provides a means of support for the electric motor Ill which drives the blower or fan II on the shaft I2. The blower II delivers air against and about the closed end wall 3 of the pot. The motor I0 may be provided a an opening 21 in the housing 1.

with, or include any suitable means for variably controlling the rate of rotation of the fan II. I illustrate, for example, the control knob Illa.

"Mounted within the pot is avaporizing container, shown as the cup generally indicated as I3 and herein shown as having a bottom wall I4, a circumferential side wall I5, and a removable top wall I6 provided with any suitable gas outlet aperture ll. '11; will be understood that the wall lli may, under some circumstances, be omitted, leaving the top of the cup open. The cup I3 may be. supported by any suitable structure. I illusstrate, for example, the support I8 extending between the pot wall 2 and the bottom I4 of the vaporizing cup.

The support I8 is preferably of heat conducting metal and of substantial mass. As will later appear, it is aligned below the area upon which drops of fuelwill fall. It serves as an efficient means for transmitting or conducting heat to the area of contact between the falling drops and the bottom I4 0f the vaporizing cup. It will be understood that any suitable fit or connection may be employed, sufficiently tight to prevent leakage. If necessary, welding can be employed.

An important feature of the invention is the delivery to the vaporizing zone, within the cup I3, of a controlled or metered supply both of liquid fuel for vaporization and of air in proper quantity and velocity to form, with the vaporized fuel, a dry gas. It is important that the liquid fuel be completely gasified. A convenient method or structure for supplying the air and fuel includesthe below described control device or assembly generally indicated as A. It is effective, as; will later appear, to maintain a proper ratio between the air and the liquid fuel supply. The control housing generally indicated at 28 may be mounted by any suitable bracket 2:, preferably properly insulated, upon the outer casing or housing I, It will be understood that liquid fuel is delivered through the lateral outlet duct 22 to the vertical discharge duct 23, aligned with said cup I3. The duct 23 is open to the atmosphere as at 24, at a level above the level of the liquid fuel in the control housing 2!). It may terminate in any suitable nozzle 25 from which droplets ofv liquid fuel may be delivered. The nozzle 25, as amatter of convenience, may be surrounded by a sighting member 26- extending into or covering Aligned with the nozzle 25, and extending upwardly into the interior of the sighting member 26, is the air tube 28 which'passes through and fills any suitable aperture 29 inthe pot wall' 2' and extends downwardly through the aperture II, into the interior of the cup I3. The cup may advantageously be made cylindrical, and coaxial with the tube 28. The tube 28 has a restricted bottom discharge portion 36 which terminates a short distance above the bottom I4 of the vaporizing cup. It may be provided with a plurality of air outlets 3|, located at intervals along its length.

The area of the space or gap 32, about the top of the tube 28, should be large enough to create a pressure within the interior of the tube 28, greater at the top than atlthe bottom, so that the air will flow downwardly through the tube 28. If the sighting member 26 is transparent, or has a transparent window, no sighting aperture is necessary. However, I may conveniently employ a sighting aperture 33. It may be advantageous to have some of the apertures 3| located above the top of the vaporizing cup, as shown at 3Ia.

As an essential factor in maintaining the fuelair ratio, it is necessary to carry a pressure in the control unit A, above the fuel in the control unit, proportional to the speed of the fan or blower I I. I obtain this result by employing an air inlet duct 35 which has an air intake aperture 36 located adjacent the tips or delivery edges of the blades of the fan or blower II, the plane of the opening 36 being normal to the direction of air delivery from the tips of the blades. I may also employ the duct 35 as a safety means for cutting off further flow of fuel to the burner, as I will later point out in detail. Thus I illustrate the warpin bar or bimetal strip 31, having one end secured, as at 38, to the inner face of the outer air housing I. The free end 39 passes through a stirrup 40 on the duct 35. The duct 35 is slidably mounted in any suitable fitting 4 I the upper opening of which is above the level of the fuel in the control A, this being shown at 42 in Figure 4.

It will be understood that when the burner goes out the warping bar 31 will move the duct end- Wise in its bearing or fitting 4I. Any suitable actuating connection may be employed whereby, when the warping bar 31 moves the duct 35, any suitable linkage or connection, as shown at 42a, is actuated or employed to trip the suitable mechanism below described, in order to out off further and its lever 55a. The interior of the space surrounded by the outer wall 20 constitutes a primary float chamber. A part of the interior, however, is separated by a dam I, defining an open topped and normally empty float chamber. If a predetermined excess of fuel is admitted to the main float chamber, the surplus fuel will spill over the dam 51 and elevate the supplemental or safety float 56. An elevation of the float 56 is effective to raise or rotate the trip lever 58. When the lever 58 releases the trigger 58a, the valve stem 54 is urged into closing position and further supply of fuel is out off. It will be understood that the linkage 42a is effective to obtain the same result, when the warping bar 31 raises the air duct 35, in response to a predetermined drop in temperature of the burner. Thus in the event of to rotation of the fan II.

4 burner failure, the further supply of fuel to the nozzle 25 is shortly automatically cut off, just as if the float 56 had responded to an excess rise in liquid fuel level.

The actual metering of the supply of liquid fuel to the burner is obtained as follows:

The liquid level may be considered as indicated at X. The liquid surrounds a tube or standpipe 60. The standpipe is sealed to the cover 6I which in turn is sealed to the casing or housing 20, so that the air space Y, above the level of the liquid fuel in the control A, is sealed from the atmosphere, but responds to the pressure of air delivered upwardly along the duct 35 in response It will be understood that there is no flow of air through the housing or through the space Y, a static pressure being provided. The standpipe 60 is provided with one or more duct apertures 62, which are located below the top level X of the liquid fuel. It will be noted that the lower end of the standpipe 60 interflts with and is in sealed relation with the upwardly extending support or guide tube 63. Oil flowing by gravity through the inlet or inlets 62 will rise in the cylindrical space 64, between the inner face of the standpipe 60 and the outer face of the valve cylinder or hollow stem 65. The interior of the valve stem is vented to the atmosphere. I show, for example, vents 66 and 68. The hollow sleeve or ring I0 is upwardly thrust by the compressed coil spring II, the bottom of which abuts against the normally fixed abutment I2. The ring III is thus normally thrust upwardly, and seats against the lower edge I3 of the cylindrical valve stem 65 and moves it up as far as its adjustment permits. The upper adjustment of the movement of the valve stem will later be described. The oil which flows upwardly into the space 64 reached the level X by gravity and rises somewhat above it by capillary action. It thus reaches the outlet aperture or apertures I4, rising completely above the upper, outer edge of any such aperture. Whatever oil is discharged through the aperture or apertures I4 is free to drop downwardly through the space within the coil spring II and flow through the fitting I5, and outwardly along the duct 22 to the vertical delivery duct 23. The valve stem 65 may be set by rotation of the knob I6, which controls a cylindrical portion 11, having a cam track I8, shown as receiving the fixed cam I9. Thus rotation of the knob I6 operates against the coil spring II, which spring, through the ring I0, forces the hollow valve stem 65 up as far as is permitted by the cam arrangement above described. In addition, and in order to fix the desired relationship of the cam, I may employ an adjusting screw 80, in the knob I6, which abuts against the upper end of the solid portion 61 of the valve stem. It will further be understood that if I move the knob and cam upwardly, and Withdraw the valve stem or cylinder 65, the spring II is then effective to raise the ring I0 high enough to mask and close the aperture or apertures 62, thus preventing any further flow of liquid fuel to the burner. In order to permit removal of the knob I6, I may generate the cam slot in such fashion as to permit clearing the knob and its associated cylinder II from the cam pin I9 at either end of the possible camming excursion. I show in Figure 6, a generated cam slot which will operate satisfactorily, with a total are of movement of the order of to I The actual operation of the metering device is unconventional and entirely contrary to previous practice in the liquid fuel valve control art. Referring, for example, to. the enlargeddiagram:- matic showing of Figure 5, and considering only single apertures, the outer aperture 62 is located definitely below the level X of the liquid and therefore liquid will flow, under the influence of gravity, to the interior space 64., which is vented to the atmosphere. However, the actual liquid level in the space 64 is not at the X level indicated in dotted line, but is actually above the. Xlevel, as at XX. Thus the inner aperture 14, although it extends at least in part above the outside X level, is actually, on its outer face, located perceptibly below the capillary level within the space 64 indicated at Z. The liquid, in the aperture 14, defines an inclined surface having some of the characteristics of the angle of repose of solidvparticles, or of the surface of a liquid drop. In practice, the oil will ooze from the aperture 14- in a continuous flow. As the liquid head: is raised, and the force of gravity is increased, the rate of liquid flow increases. In the usual fiow.of liquids through an orifice, the flow of liquid is proportional to the head.

With a suitable size orifice placed at the level of the liquid, it can be shown that the fuel increase will be proportional to the increase of air pressure, according to the laws governing the flow of liquids over a weir. Thus a very rapid increase of flow is obtained with a very small liquid head. To give a typical instance, when the desired fiow for pilot fire is 2 cc. per minute, the distance of the head XX of the liquid above the bottom of the orifice M is of the order of .01", the air pressure on the burner being about .02 W. '0. As soon asthe air pressure is increased to .04 W. C., which is sufficient for an effective low fire, the level XX rises to .03, and the effective width of the weir formed by the lower surface of the aperture 14 increases in such fashion that the rate of flow increases not only in proportion to the depth of liquid running over the weir, but also in proportion to the increase of the effective width of the weir up to the full diameter of the orifice 14. If the diameter of the orifice 14 isof the same order of magnitude as the pressure measured in inches of water, then, in the above example, where I employ an orifice of a diameter of .07, the level XX will reach the maximum width of the orifice with a change of level less than .035", one-half the diameter of the orifice. As soon as the level XX reaches the level of the horizontal maximum diameter of the orifice 14, any further increase in level will decrease therate of increase. And, with the addition of .035 W. C. of pressure head, the orifice 14 will be completely submerged. The rate of flow through the orifice will then be proportional to the head. But, inasmuch as the air supply for combustion is also proportional to the increase in blower pressure, the'rate of flow will at all times be a function of the head, and proportional to the flow of air to the burner. The flow of the fluid is proportional to the squareroot of the head or pressure on the fluid.

In a system using a pilot and a blower to supply air for combustion, it is desirable to deliver the air at a pressure of between .02" and .03" W.'C., so that the normal back draft down the chimney, due to wind or other causes, will not extinguish the small pilot flame. It is also desirable to operate the lowest heating flame at a rate of approximately 6 cc. to 8 cc. per minute, but at an air pressure of approximately .04 W. C. At this rate of combustion it is important burner.

that the air, to fuel ratio be such that there is sufficient air for complete combustion, but not an excessive amount. This condition exists on up to the, maximum rate of combustion for which the burner is designed.

But the conditions as to air to fuel ratio for the pilot stage are not the same. For pilot operation it is important to have sufficient air at the proper pressure for pilot combustion, and

also to have a great deal of excess. air, to care for fluctuating atmospheric conditions, and also to carry away the heat generated by the. pilot.

It is significant that the above effect cannot be obtained if the inner orifice 14 is actually below the outside liquid fuel level X.

As shown in Figure 7, I may substitute for the warping-bar 31 the connection 31a between the duct 35 and the vaporizing cup orcontaine l3. Air leakage may be limited by the plate 3112 connectedto the supporting bracket 310 by the pin 37d. The member 310 extends through any suitable slot 31c and is partially housed in the exterior member 3'. It will thus be seen that, in response to movement of the free end of the warping bar 3111, the plate 31b is moved toward and away from close relationship to the slot or passage 31c. Thus air leakage through the slot is thermostatically controlled.

It will be realized that whereas I have described and illustrated a practical and useful invention, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing.

The use and operation of my invention are as follows:

I illustrate herein an improved liquid fuel burner, in which as shown in Figure 1, a dry gas is obtained, in a zone of vaporization within the burner, and is burned in the burner, the gas being formed during the normal operation of the Whereas I have illustrated my invention as applied to the horizontally axised pot type burner, it will be understood that it can be applied to pot type burners of the vertical, inclined, and also the inverted type. It will further be understood that my means of and method for providing a dry gas may be employed to supply a gaseous fuel to other burners or for other purposes.

In the particular application of my invention herein shown, I employ a vaporizing cup I3,

within a burner pot I; the vaporizing cup receives all of the fuel which is burned in the pot. The fan ll delivers the air necessary for the formation and combustion of the final fuel. The fan H also assists in the coordinated control of the air and fuel supply not only to the burner as a whole, but to the vaporizing cup.

By the liquid fuel control means above de scribed, a metered supply of fuel is delivered downwardly through and along the air tube 23. The droplets of fuel strike the bottom M of the cup l3, at or in alignment with the combined support and. heat storage element l8. Air is supplied directly to the interior of the vaporizing cup or zone, by the tube 28, through its apertures 3| and 3|a.

With respectto the control part of the invention, the space Y of the control unit A is subjected to static pressure, through the duct 35 and the inlet 36, responding to the air delivery from the fan I I. This direct pick up of air pressure from the fan blades is important.

However, my invention may be employed in connection with a manual metering of fuel in connection with the use of atmospheric air pressure.

In the event that the burner goes out, the warping bar 31 provides a safety factor, working through the air duct 35 which actually is used as a means for tripping the control mechanism to cut off further liquid fuel flow.

It will be understood by increasing the rate of air delivery of the fan II, I at the same time increase the supply of air for combustion, and increase the rate of flow of liquid fuel to the vaporizing zone. Similarly, a drop in the air delivery rate results in a reduction of the rate of liquid fuel delivery for vaporization. The result is a highly efficient fuel forming and burning mechanism and method, which results in a clean fire and a minimum deposit of free carbon.

It should be kept in mind that at low feed the space between the members 60 and 65, in connection with the aperture 14, acts as a trough, in the sense that the upper edge of the aperture does not restrict the flow. It is only as the oil level rises, that the upper edge of the aperture 14 drops below the level of the oil, causing the orifice to become a restriction.

I claim:

1. In a liquid fuel burner and control means therefor, a burner pot having a plurality of air inlet apertures, spaced circumferentially around the pot and located at various distances from the end of the pot an air housing surrounding said pot, a fan adapted to draw air into said housing from the atmosphere, means for variably controlling the rate of rotation of said fan, said fan having a plurality of blades, a vaporizing container in said pot, a liquid fuel flow control unit, a liquid fuel delivery nozzle connected to receive liquid fuel from said unit, and adapted to deliver liquid fuel to the interior of said vaporizing container, means for delivering air, from the space between said pot and air housing, to the interior of said vaporizing container, and means for proportionately varying the rate of flow of liquid fuel to said container simultaneously with variations in the rate of flow of air to said container, including an air intake duct extending from adjacent the delivery edge of said fan blades to communication with the interior of said liquid fuel flow control unit, means mounting said duct for longitudinal movement, cut-off means in said control unit to prevent further fuel delivery, an actuating-connection between said duct and said cut-off means, and a thermostatic element, subjected to the heat of said pot, in actuating relationship with said duct, and arranged to operate said cut-off in response to decreasing temperature.

2. In combination, a pot type burner having a burner pot and an air housing surrounding said pot, means for delivering liquid fuel to the interior of said pot for vaporization and combustion, a fan adapted to deliver air to the interior of said air housing, about said pot, means for controllably varying the rate of rotation of said fan, and means for controlling the rate of liquid fuel delivery to the interior of said pot, including a liquid fuel flow control unit, a liquid fuel delivery duct extending from said unit to the burner, said unit including a housing defining a liquid fuel chamber closed to the atmosphere, and an air duct having an inlet opening adjacent the blades of said fan, and extending to communication with the interior of said fuel chamber, a cutoff means for said control unit adapted to prevent further fuel delivery, means mounting said air duct for longitudinal movement, an actuating connection between said air duct and said cut-off means, and a thermostatic element, subjected to the heat of said pot, connected to said duct, and arranged to operate said cut-off in response to decreasing temperature.

3. In a pot type burner, an outer housing, a horizontally axised pot positioned within said outer housing, said pot having a closed end wall, a circumferential generally cylindrical side wall, and a centrally apertured flame ring partially closing the otherwise open end of the pot, said circumferential side wall having a plurality of primary air inlets spaced circumferentially thereabout and located at various distances from the ends of the pot, and having secondary air inlets adjacent the said flame ring, a vaporizing container mounted within said pot, intermediate the ends of the pot, a generally vertical air inlet tube extending downwardly into said vaporizing container, means for delivering air under pressure to the space within said housing and surrounding said pot, the interior of said tube being in communication with the space between said housing and pot, whereby air is delivered to the apertures of said circumferential side wall, and through said tube, and means for delivering liquid fuel to the interior of said vaporizing container, including means for dropping liquid fuel downwardly through the interior of said tube.

4. The structure of claim 3, including the provision of apertures in said air inlet tube, located at various levels within said vaporizing container.

5. The structure of claim 3, including means for proportionately varying the rate of fuel delivery and the rate of air delivery to the interior of said vaporizing container.

JAMES L. BREESE.

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

UNITED STATES PATENTS Number Name Date 768,525 Edwards Aug- 23, 1904 768,798 Goodwin Aug. 30, 1904 840,657 Reed Jan. 8, 1907 883,236 Rehbein Mar. 31, 1908 897,506 Young Sept. 1, 1908 946,581 Rork Jan. 18, 1910 951,722 Brabham Mar. 8, 1910 967,089 Wadley Aug. 9, 1910 967,595 Wright Aug. 16, 1910 992,404 Burk, et al. May 16, 1911 1,455,810 Rowley May 22, 1923 1,583,238 Scudder May 4, 1926 1,923,614 Clarkson Aug. 22, 1933 2,348,721 Breese, et .al. May 16, 1944 2,369,999 Behrendet, et al. Feb. 20, 1945 2,393,248 Hayter, et al. Jan. 22, 1946 2,418,709 Hayter Apr. 8, 1947 FOREIGN PATENTS Number Country Date 828,121 France Feb. 7, 1938

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