US2313568A - Combustion apparatus - Google Patents

Description

' March 9, 1943. J. w. MILLER COMBUSTION APPARATUS Filed Dec. 6, 1939 3 Sheets-Sheet 2 T mf 6m M m m@ March 9, 1943.

COMBUSTION APPARATUS Filed Dec. 6, 1939 3 Sheets-Sheet 3 54 0 a 0 15 a o INVENTOR. JOHN W M/. 4 5E ATTORNEY.

J. w. MILLER 2,313,568 I Patented Mar. 9, 1943 COMBUSTION APPARATUS John' W. Miller, Lansing, Mich., assignor to Motor Wheel Corporation, Lansing, Mlch., a

' corporation of Michigan Application December 6, 1939, Serial No. 307,134 Claims. (01. 158-91) This invention relates to oil burners of the vaporizing pot type, and more particularly to the means for controlling the .air admitted thereto.

Previousvaporizing pot type burners, and by that term is meant pot type burners having air inlet openings in the side walls thereof and in which the height of the fire may be regulated by varying the rate at which oil is supplied thereto, have not been providedwith really efiflcient air control means. This is due to the fact thatair is admitted through all of the air inlet openings in the burner side wall at all stages of combustion, whereas the lower limit of the zone of combustion may be located at various heights from a point adjacent the bottom of the burner up to the opening in the top wall.

In order to promote efiicient operation of the burner it is necessaryto coordinate the quantity of air admitted to the burner with the quantity of fuel which is delivered thereto. This has been done in previous burners by regulating the draft on the burner. Such a system has the disadvantage, however, of reducing the velocity of the jets of air entering the air inlet openings at the lower stages of operation of the burner, and as a result the flame is inclined to be smoky. On the other hand, if suflicient air is delivered to the lowermost air inlet openings to produce a clean fire at the lowest stage of operation, then a great excess of air is admitted to the burner in the openings above the flame which have no other efiect than to absorb heat and carry it up the chimney.

Accordingly, the principal object of this invention is to overcome the disadvantages of previous types of burners by not only coordinating the air and fuel supplied to the burner but in delivering the air only to the zones in which vaporization, premixing and combustion of the fuel occur.

This is accomplished by providing a plurality of closure means which confine the admission of air to the aforementioned zone or zones, and which closures can be opened successively as the fuel supply is increased.

For a more detailed description of the invention reference is now had to the accompanying drawings, wherein- Figure 1 is a vertical cross-sectional view of an oil burning heater having a vaporizing pot type burner therein in which the invention is embodied;

Figure 2 is a fragmentaryplan view of a portion of the air control and fuel regulating means of the device shown in Figure 1;

v .ma v www Figure 3 is a fragmentary elevational view of a portion of the fuel regulating means and the air control means shown in Figure 1;

Figure 4 is an enlarged fragmentary cross-sectional view of a portion of the device shown in Figure 1;

Figure 5 is a cross-sectional view of a modified form of the invention showing in diagrammatic form the wiring diagram for the controls; and- Figure 6 is a view of the developed surface of the control drum for the device shown in Figure 5. V v

The modification shown in Figures 1 to 4 is embodied in a radiant type of space heater. The heater comprises an outer casing I supported on legs i I. The legs I l consist of a pair of crossed straps with their ends spaced sufflciently to admit air to the lower portion of the casing. The casing consists of an upper combustion chamber Illa and a lower air jacket l2. A flue outlet l3ohav ing an automatic draft regulator H pivotally mounted in one side thereof connects the combustion chamber [0a to a chimney l5 to permit the escape of exhaust gases from the interior of the combustion chamber.

Mounted within the air jacket l2 of the casing in is a vaporizing pot type burner I6. The burner includes an oil pan ll forming the bottom wall of the burner. In the bottom of the oil pan [1 and adjacent one side of the burner is a depression l8 to collect the fuel admitted to the burner at low fire whereby to provide for ready ignition of the fuel. Secured to the upper edge of the oil pan l1 and in sealed engagement therewith is a substantially cylindrical side wall iii. The side wall It! has a plurality of vertically spaced horizontal rows of primary air inlet openings 20 therein to permit the entrance of air to the burner. Near the upper edge of the burner is a single horizontal row of secondary air inlet openings 2i. Located immediately below the secondary air inlet openings is a top wall 22 having a large central opening 23- therein. An anti-explosion baffle 24 is positioned directly above the top wall 22 and above the secondary air inlet openings 2|. Intermediate the top and bottom rows of primary air inlet openings 20 is a centrally apertured inclined partition 25. The lower edge of the partition 25 is located directly above the depression I 8 in the oil pan l1 and above the lowermost row of air inlet openings 20. Its upper end is positioned below the two uppermost rows of primary air inlet openings 20.

- Mounted on the side wall of the casing III is a metering device 26. The metering device is connected to a suitable source of fuel and is also connected to the burner by means of a pipe 21 for supplying fuel to the burner. The metering device is equipped with a fuel regulating valve, not shown, adapted to be rotated by a shaft 28 extending upwardly therefrom. Secured to the shaft 28 is a pointer 28a. On top ofthe metering device 28 is a dial (see Fig. 2) which together with the pointer 28a indicates the fuel control valve setting. The position marked "Start" shows the setting for low fire in the burner and 9 indicates the high setting.

Surrounding the burner side wall at points intermediate the upper and lower edges thereof are three annular rings 32 in sealed engagement with the air Jacket I2 and the wall of the burner I8. These rlngs'form with the air jacket I2 and the burner side wall IS a plurality of vertically separated air compartments 33, 34, 35 and 36. The lowermost compartment is open at all times to the atmosphere through the openings between the legs II. The other three compartments 34, 35 and 36 are provided with air inlet ducts 34a, 35a and 360 respectively at one side. The ducts are closed by pivotally mounted valves 31, 38 and 38 respectively, shown in closed position in full lines, and in open position in dotted lines in Figure 4.

Pivotally attached to the respective valves 31, 36 and 33 are links 40, 4| and 42. The upper eniis of the links 40, H and 42 are pivoted to levers 43, 44 and 45, respectively, the latter being pivotally secured to a bracket 46 mounted on the casing I0. Rigidly secured to the levers 43, 44 and 45 respectively, and extending laterally therefrom, are cam followers 41, 48 and 49. The cam followers cooperate with three cams 28, 30 and 3| secured to shaft 28 and rotatable therewith. The cam surfaces of the cams are so designed that as the shaft 28 is rotated counterclockwise (as viewed in Figure 2) or from the 011" position to position 9, the cam followers 41, 48 and 49 will be successively raised in that order, thus successively opening the valves 31, 38 and 38.

When the burner is operating at its lowest stage the fuel control valve will be nearly closed, or in other words, in such a position that the pointer 28a points to the word Start on the dial on the top of the metering device 26. Under these conditions the cams will all be inoperative and the valves 31, 38 and 38 will all be closed. Consequently, all of the air necessary for combustion will enter the burner through the two lowermost rows of air inlet openings 20. When it is desired to increase the amount of heat generated by the burner, the shaft 28 is rotated in a counter-clockwise direction (as viewed in Figure 2). When pointer 28a reaches point 3 on the dial cam 28 will begin to raise the corresponding arm 43 and open the valve 31, admitting air to the row of air inlet openings 20 communicating with compartment 34. A still further increase in the rate of fuel supply will be caused by continued rotation of the shaft 28. When pointer 28a reaches position cam 30 comes into action and opens valve 38. In the same manner, cam 3| raises valve 38 when the shaft 28 has been rotated so that the pointer is at position '7 on the dial.

Thus, it will be seen that the air admitted to the burner is regulated in accordance with the quantity of fuel delivered to the'burner. Also,

burner in which vaporization, premixing and combustion occur.

Figures 5 and 6 show a modified form of the invention. This device not only controls the air 5 in proportion to the quantity of fuel admitted to the burner, but maintains by means of a blower a constant air supply to the burner at each stage of its operation. The invention shown in this modification is embodied in a radiant heater somewhat similar to that previously described, but in which the entire casing is completely closed except through ducts at the side of the burner.

The heater consists of a casing I50 having an air jacket I5I at its lower end. Mounted within the casing I50 is a burner I52 of exactly the same type as that previously described. Surrounding the burner is a pair of spaced annular rings I53 and I54 which divide the air jacket I5I into three compartments I55, I56 and I51. At one side of the burner, a manifold I58 is located. This manifold has three arms or ducts I58, I60 and I6I which communicate with the three compartments I55, I56 and I51 respectively. The other end of the manifold communicates with the housing of a centrifugal blower I62 driven by a multiple speed motor I63. The motor is provided with four motor brushes I86, I81, I88 and I89.

Pivotally mounted within the ducts I60 and I6I of the manifold are valves I64 and I65 respectively. The valve I64 is adapted to be actuated by a solenoid I66 mounted exteriorly of the duct I6I and a similar solenoid I61 is pro- -vided for actuating the valve I65.

the air is admitted only to the zones within the Secured to the exterior of the casing I50 is a conventional fuel control I68 which is connected to the burner by means of a pipe I69. Extending upwardly from the fuel control I68 is a rotatable shaft I10 which is adapted to actuate the metering valve in the fuel control. Mounted on the shaft I10 is a control drum I1I, a development of the surface of which is shown in Figure 6. This control drum has a plurality of horizontal metallic strips I12, I13, I14, I15 and I16 secured to the exterior surface thereof. The strips I12, I13 and I14 are connected together at their adjacent ends by means of a suitable electric conductor I11. Strips I14 and I15 are connected by a conductor I18, and strips I15 and I16 are connected by a conductor I18.

Mounted on the top of the housing of the oil control device I68 is an upstanding bracket I60 which supports five control brushes I8I, I82, I83, I84 and I85. Each of these brushes is insulated from the others and is mounted in a manner to contact the metal strips I12 to I16 respectively on the drum.

The wiring diagram of the circuit of-this construction is plainly indicated in Figure 5, so it is believed to be unnecessary to discuss it in detail.

The fuel control valve is adapted to be rotated by shaft I10 to eleven different positions. In one of these the fuel control valve is completely closed. The second position is labelled Start (see Figure 6) and thereafter the different positions are numbered 1 to 9" respectively. Assuming that the fuel control valve has been set to the Start" position, the valves I64 and I65 are closed and the motor will be operating at its lowest speed. Under these circumstances control brush I8I touches strip I12 and control brush I85 is in contact with stijp I16. Current then flows through the motor by way of motor brushes I88 and I86. Allof the air for combustion will then be supplied through the duct I58 and at a relatively low velocity.

.operation of the burner.

As the shaft I is rotated to open the fuel valve, more oil will b supplied but the motor will continue to operate at its initial speed until the valve is opened to the position marked'3 in Figure 6. At this point control brush I 85 goes 5 out of operation and current flows through the motor by way of brushes I81 and I89. At the same time solenoid I86 is actuated by the closing of the circuit through the strips I14 and I and conductor I18. This will speed the motor up and thereby deliver more air to the burner, and the air will then be delivered .through compartments I55 and I56.

Still further rotation of the control drum from the points marked 6 to the position numbered 9 will throw the control brush I84 out of the circuit and cause control brushes I 82 and I83 to contact strips I13 and I14 respectively.. This will energize solenoid I61 and open valve I85 while leaving valve I64 open. At the same time the current will flow through the motor by way of motor brushes I88 and I89 and cause it to operate at its highest speed.

It will be apparent that in this modification the fuel supply and air supply are maintained at substantially the correct proportions at all times, and the quantity of air delivered to the .burner cannot fluctuate as in the case of any of the previous burners which are dependent upon natural draft.

It is, of course, possible by multiplying the number of air compartments, manifold arms and valves, as well as the number of speeds of the motor, to increase the quantity of air delivered to the burner at each of the numbered'settings of the fuel control valve instead of at positions 3 and 6 only. However; from a practical standpoint the number of valves and the number of motor speeds disclosed will'provide very efllcient More motor speeds and 40 valves necessarily complicate and increase the expense of the regulating system.

From the foregoing it will be seen that although the diflerent modifications vary in detail they have as their basic features the coordination of the fuel and air supply to maintain substantially constant a predetermined ratio of fuel and air, and they admit the air to the burner at the points where the air is most needed to provide a clean fire at all stages of operation of the burner.

The scope of the invention is indicated in the appended claims.

I claim: I

l. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall, each compartment being in communication with some of said air inlet openings andbeing arranged one above another, each of said compartments having an aperture therein for the admission of air thereto, a valve in the aperture in each of the upper compartments only for regulating the air admitted therethrough, means for delivering liquid fuel to the burner in reguiatable quantities, and means operatively connected to said fuel delivering means for successively opening said valves in order from the lowermost to the uppermost valve and for closing the. same in the reverse order as the quantity of fuel delivered to the burner is respectively increased or decreased.

2. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall thereof, each compartment being in communication with some of said air inlet openings and being arranged one above another, each of said compartments having an aperture therein for the admission of air thereto, a valve in the aperture in each of the upper compartments for regulating the air admitted therethrough, means for delivering liquid fuel to the burner in reguiatable quantities, and means coupled with the fuel regulating means and connected to the valves for successive- 1y opening'the latter in order from the lowermost to the uppermost valve and for closing the same vin the reverse order as the quantity of fuel delivered to the burner is respectively increased or decreased.

3. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall thereof, each compartment being in communication with some of said air inlet openings and being located one above another, each 0f' 'S3.id compartments having an aperture therein for the admission of air thereto, a fan, a multiple speed motor for driving said-fan, a manifold connected at one end to said fan and having a plurality of separate arms connected to the'compartments at the respective apertures therein, a valve in the aperture in each of the upper compartments, means for delivering liquid fuel to the burner in regulatable quantities, means coupled with the fuel regulating means for increasing or decreasing the speedof the fan as the quantity of fuel is increased or decreased, and additional means coupled with said fuel regulating means and con nected to the valves for'successively opening the latter in order from the lowermost to the upper-- mostvalve and for closing the same in the reverse order'as the quantity of fuel delivered to the burneris respectively increased or decreased.

4. Combustion apparatus comprising aburner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of the air admitted therethrough, and means for supplying liquid fuel to the'burner and for regulating the quantity supplied thereto, said means including" a rotatable shaft, a plurality of cams on said shaftrotatable therewith, and a'plurality of cam followers associated with said cams and connected to the respective valves, said cams being arranged on said shaft in a manner to suecessively open the valves in order fromthe lowermost to the uppermost valve and to close the same in the reverse order as the shaft is rotated in one direction or the other to increase or decrease the quantity of fuel supplied to the burner.

5. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall, each compartment being in communication with some of said air inlet openings and arranged one above another, each of said compartments having an aperture therein for the admission of air thereto, a valve in the aperture in each of the upper compartments only comprising a blade pivotally mounted on a horizontal axis above the center of the blade and being of a size to completely close said aperture in one position of the blade, means for delivering liquid fuel to the burner in regulatable quantities, and means operatively connected to said fuel delivering means for successively opening the valves in order from the lowermost to the uppermost valve and for closing the same in the reverse order as the quantity of fuel delivered to the burner is respectively increased or decreased.

6. Combustion apparatus comprising a burner of the vaporizing pottype having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall,

each compartment being in communication with some of said air inlet openings and being arranged one above another, each of said compartments having an aperture therein for the admission of air thereto, a valve in the aperture in each of the upper compartments for regulating the air admitted therethrough, and means for supplying liquid fuel to the burner and regulating the quantity of fuel supplied thereto, said means including a rotatable shaft and means connecting said shaft to the respective valves to successively open the valves in order from the lowermost to the uppermost valve and toclose the same in the reverse order as the shaft is rotated in-one direction or the other to increase or decrease the quantity of fuel supplied to the burner.

7. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall, each compartment being in communication with some of said air inlet openings and being arranged one above another, each of said compartments having an aperture therein for the admission of air thereto, a valve in the aperture in each of the upper compartments for regulating the air admitted therethrough, and means for supplying liquid fuel .to the burner and for regulating the quantity supplied thereto, said means including a rotatable shaft, a plurality of cams on said shaft rotatable therewith, a plurality of levers oivotally connected to said apparatus, cam followers on said levers associated with the respective cams, and means connecting said levers to he respective valves whereby rotation of said cams will cause movement of said valves, said cams being arranged on said shaft in a manner to successively open the valves in order fromthe lowermost to the uppermost valve and to close the same in the reverse order as the shaft is --'certain of said groups of openings, and means coupling said closure means to said fuel regulating mechanism including a rotatable shaft, a plurality of cams on said shaft rotatable therewith, and means connecting said cams to said closure means whereby said closure means are moved to open an increasing number of groups of air inlet openings in order from the bottom to the top of the burner as the fuel regulating mechanism is operated to increase the fuel supplied to the burner.

-9. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically separated groups of horizontally spaced apart air inlet openings in the side wall thereof, independent closure means spaced from the burner side wall for each of the groups of air inlet openings except the lowermost group, means for delivering liquid fuel to the burner in regulatable quantities, and means operatively connected to said fuel delivery means for successively opening said closure means in order from the lowermost to the uppermost and for closing the same in the reverse order as the quantity of 'fuel delivered to the burner is respectively increased or decreased.

10. Combustion apparatus comprising a burner of the vaporizing pot type having a plurality of vertically and horizontally spaced apart air inlet openings in the side wall thereof, a plurality of separate air compartments surrounding the burner in sealed engagement with the side wall thereof, each compartment being in communication with some of said air inlet openings and being located one above another, each of said compartments having an aperture therein for the admission of air thereto, a fan, a motor for driving said fan, a manifold connected at one end to said fan and having a plurality of separate arms connected to the compartments at the respective apertures therein, a valve in the aperture in each of the upper compartments, means for delivering liquid fuel to the burner in regulatable quantities, means coupled with the fuel regulating means for increasing-or decreasing the quantity of air supplied to the manifold by the fan as the quantity of fuel is increasedor decreased, and additional means coupled with said fuel regulating means and connected to the valves for successively opening the latter in order'from the lowermost to the uppermost valve and for closing the same in the reverse order as the quantity of fuel delivered to the burner is respectively increased-or decreased.

JOHN W. MILLER.

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