US2164225A

US2164225A - Liquid fuel burner

Info

Publication number: US2164225A
Application number: US112246A
Authority: US
Inventors: Earl C Walker
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1936-11-23
Filing date: 1936-11-23
Publication date: 1939-06-27
Anticipated expiration: 1956-06-27

Description

June 27, 19 39. E. c WALKER 2,164,225

LIQUID FUEL BURNER Filed Nov. 25, 1936 2 sheets-sheet 1 June 27, 1939. v E. c. WALKER 2,164,225

LIQUID FUEL BURNER Filed Nov. 23, 1936 2 Sheets-Sheet 2 I I I I l I ll 1/ Patented June27, 1939 UNITED STATES PATENT OFFICE national New Jerlcy Company, a corporation of Application November 23, 1936, Serial No. 112,246

14 Claim.

This invention relates to a hydro-carbon burner.

The principal objects of the invention are to procure efficient combustion and to burn a relatively large amount of fuel in a given combustion chamber space, and to eliminate the need for refractory linings in the combustion chamber.

This object and other objects which will be apparent are accomplished by spraying the fuel as finely as possible, preferably with alrpressure, directing the atomized fuel through the heat zone of the combustion chamber so that it is partially vaporized before reaching the combustion chamber, partially burning the fuel with a. limited supply of air, providing a combustion chamber of such shape and proportion that high turbulence is obtained by the main air supply from a blower, and maintaining the mixing and turbulence during combustion by the shape of the combustion chamber. supply is caused to scrub the exterior wall of the combustion chamber, thereby effectively cooling same, and at the same time, preheating the air and thus affording better combustion.

In the drawings:

Figure 1 is a top plan view of a burner embodying the invention;

Figure 2 is a vertical section on the line 2-4 of Figure 1;

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

Figure 4 is a sectional detail showing a modified shape of a combustion chamber.

The casing which houses the burner is made up of a cylindrical upper casing member ill and a cylindrical lower casing ii telescopically received by the upper casing member. The two members are fitted for reciprocation with respect to each other for adjusting the nozzle II, which is carried by the upper casing member, with relation to the fire bowl. A clamp ring I3 is provided for clamping the two casing members in a fixed position with respect to each other. The lower casing member H is seated on an outwardly extending flange M which is an integral part of the fire pot i5 which forms the combustion chamber proper.

The fire pot i5 is of a particular shape designed to maintain a high state of turbulence set up by the manners in which theair and burning fuel are introduced therein. The combustion chamber may also be described as an oblate spheroidal shaped bowl, having its top edge bent over outwardly on a suitable radius forming the flange H for supporting the lower casing member II and having a circular aperture IS in the bottom of the bowl centrally thereof.

An air box It substantially cylindrical in shape surrounds the fire pct in spaced relation thereto. The upper edge of the air box is fitted into an annular recess formed in the flange ll of the fire pot. Clamping lugs are provided for securing As an additional feature, the main air the lower casing member II and the air box I. in position against the flange ll.

A main air conduit 2| is connected on a tangent to the side of the air box I! for supplying air under pressure thereto. An adjustable damper 22 is v5 provided in the conduit 2 I. Air may be supplied to said conduit from any suitable blower or fan. An auxiliary air inlet conduit 23 is connected to the main conduit 2i on the inlet side of the damper 22. Said conduit extends upwardly above the upper casing l0 where it is connected to a nozzle chamber 24. A damper 23' is provided in the auxiliary conduit for regulating the supply of air to the nozzle chamber.

The nozzle chamber 24 is formed by a flanged cylindrical sleeve 25 having a conical end portion 2! to restrict the outlet from the chamber. Said sleeve is adjustable in a cylindrical sleeve 21 fitted into the end plate 28 forming the top wall of the upper casing to. Secured to the sleeve 28 is a cover plate 29 centrally through which extends the nozzle I! previously referred to. An ignition device 30 consisting of a pair of insulated terminals or electrodes also extends through the cover plate 29. A gas pilot light, not shown, may be used for ignition if desired.

A glass capped observation tube 3| is fitted into the end plate 28 to provide means for observing the condition of the flame in the combustion chamber. Insulating material 32 is applied over the plate 28 and around the upper end of the upper casing II. To provide for the outlet of burned gases, 9. series of openings 33 is formed around the upper end of the upper casing ill below the top plate 28. An outlet bustle 34 surrounds the casing and com- 3 municates with the openings 33. Said bustle is of increasing cross section from a point adjacent the tube 3| to the diametrically opposite side at which it communicates with a stack 35.

A member 35 is secured over the opening I 8 in the bottom of the fire pot. Said member is open at its center except for a central guide portion 31 and ribs 38 extending therefrom. A member 39 is secured by cap screws to the central portion 31 of the member 36. Said member is provided with an annular flange to which an air directing jacket 40 is attached. Said jacket envelops the fire pot l5 and is spaced from the bottom and curved side walls thereof. To secure the jacket in position, a plurality of bosses are formed on the fire pot. Cap screws extend through the jacket and into said bosses to secure the jacket rigidly in position. It will be noted that over the curved portion of the fire pot the jacket is closely spaced whereby all passing between the fire pot and the jacket moves at a relatively high velocity thereby scrubbing the outer surface of the fire pot walls and maintaining them at a reasonably low temperature and, at the same time, preheating the air to effect more rapid and complete combustion in the fire pot.

A vertical shaft ll slidably extends through guide openings formed centrally of the members 36 and 3!. Said shaft also extends through a fitting 42 mounted in the bottom wall of the air box. The shaft is'threaded through said fitting and provided with a lock nut so that it may be vertically adjusted and locked in such positions of adjustment as may be required.

The upper end of the shaft ll extends into the fire pot and carries rigidly mounted thereon a vaned deflector 44, surmounted by a conical shaped baflle 43. The upper side of said baille 43 is generally conical in shape being curved inwardly below the apex to provide a more streamlined surface for impingement of the products of partial combustion and air delivered from the nozzle chamber 24. The lower side of the deflector 44 is provided with a plurality of circumferentially spaced spiral vanes, as indicated in Figures 2 and 3. It will be noted that the bottom side of the deflector 44 is spaced above the bottom of the fire pot and that the lower edges of the vanes formed thereon are shaped to conform to the lower wall of the fire pot to permit adjustment with the deflector in a lowered position.

Figure 4 shows a modification in the fire pot construction designed to give a different whirling movement to the combustion products. The flre pot I5 is formed with a downward bend near the neck portion H for directing the gases downwardly. A shield or jacket 40' is closely spaced with respect to the fire pot I 5' and is carried around the curved upper portion to maintain a cooling stream of incoming air within the neck portion l'l'. It is noted that no insulating or refractory lining is shown in this form adjacent the casing II or the separate flange l4. The incoming air keeps the adjacent parts at a suinciently low temperature to prevent destruction by high temperatures.

In the operation of the burner as above described, air under a suitable pressure is supplied to the main inlet conduit 2|. The major portion of the air is delivered to the air box is. Said air passes upwardly around the jacket 40 as indicated by the arrows in Figure 2 and downwardly around the fire pot, thereby cooling its walls. This construction enables the use of a metallic fire pot,

as it can thus be maintained at a sufilciently low temperature by the direct cooling by the incoming air to prevent destruction. The incoming air is thus preheated before entering the fire pot. The preheated air then passes upwardly through the opening IS in the bottom of the fire pot and is directed spirally outwardly between the bottom of the fire pot and the bottom of the deflector 44 by the vanes thereon. The air is discharged in a substantially horizontal direction with a spiral movement around the interior of the fire pot as indicated by the dotted arrows in Figure 3.

Fuel and air under suitable pressures are forced through the nozzle I! which may be of any type producing a finely atomized spray suitable for primary combustion. Additional air for the primary combustion delivered through the air conduit 23 to the nozzle chamber 24 is discharged with the atomized fuel through the restricting member 26. When ignited said mixture burns with a partial combustion. The diverging angle of the spray is relatively small as is also that of the air stream entering with and enveloping the spray of atomized fuel, so that its spread at the point where it enters the fire pot is such, that it enters the throat of the whirling vortex ring of flame without'interfering with its whirling and rotating motion. The products of partial combustion are delivered downwardly centrally of the fire pot impinging the apex of the deflector l3. Said deflector changes the path of the mixture directing it substantially radially and horizontally as indicated by the arrows in Figure 2. The two radially projected streams, one being the partial combustion products and the other the secondary air supply, meet traveling in substantially parallel paths directed at somewhat of an angle into each other. Both the streams combine and impinge the curved wall of the fire pot. Due to the whirling of the secondary air stream about a vertical axis, as directed by the spiral vanes of the deflector 44, a spiral motion is brought about, and as the two streams meet and then pass upwardly around the curved wall of the fire pot a. whirling vortex results. The action may be described as being similar to a vortex smoke ring which is whirling about an axis through its circular core center, and simultaneously rotating in a circle about an axis passing through the center of the ring. By this means and method a thorough mixing-of air and fuel takes place which facilitates efilcient and complete combustion of the fuel particles, all within the fire pot and without requiring an excessive amount of air. Due to this condition brought about by high and systematic turbulence, the volume of the combustion chamber is greatly reduced, and combustion is completed within the fire pot. The hot burned gases are discharged around curved wall I! to the upper chamber formed by the casings I0 and I I, thus enveloping the spray from the nozzle with hot gases and inducing vaporization of the fuel in the spray. The products of combustion are finally delivered through the openings 33 and the bustle 34 to the stack 35. This burner may be utilized for heating boilers or for any other purpose. By means of a construction as above described, I have succeeded in obtaining a very complete combustion of relatively low grade fuel oils. The efficient operation is obtained largely as a result of progressive combustion and by properly and intimately mixing the secondary preheated air with the products of the primary combustion. By constructing the fire pot jacket and air flow passages, as described, I have been able to use a metallic fire pot which will stand up under conditions of operation usually requiring refractory materials. By providing a deflector, as described, the proper mixing may be controlled as desired by vertically adjusting the deflector 43 in the fire pot.

It is to be understood that I have shown and described only a preferred embodiment of my improved device for burning liquid fuels and that I claim as my invention all modifications falling within the scope of the appended claims.

What is claimed is:

1. In an oil burner having a combustion chamber means for supplying fuel, means for supplying air for primary partial combustion, ignition means and means for directing the resulting partial combustion products into the chamber, and in combination therewith, a deflector positioned in the combustion chamber to be impinged by the stream of products of the primary combustion and shaped to deflect said stream radially symmetrically in all directions substantially at right angles to its original direction, means for supplying secondary air in a spiral direction substantially parallel to the deflected stream of the products of the primary combustion, and additional means for detion, and means for supplying secondary air to the. combustion chamber including deflecting means to move the air in a spiral direction substantially parallel to the deflected stream of products of the primary combustion.

3. In an oil burner provided with a casing having a combustion chamber means for supplying fuel, means for supplying air for primary partial combustion, ignition means and means for directing the resulting partial combustion products into said chamber in an axial direction and in combination therewith, a fire pot positioned in the casing to receive said stream, a deflector positioned in the fire pot to be impinged by the stream of products of the partial combustion and shaped to deflect said products radially toward the wall of the fire pot at substantially right angles to their original direction, and means for supplying secondary air to the fire pot including means for deflecting the air to cause movement in a spiral direction substantially parallel to the deflected stream of products of the partial combustion, said fire pot being shaped to provide additional deflecting surfaces for the combined products of partial combustion and secondary air to facilitate mixing thereof and complete combustion of said products.

4. A burner comprising a vertical cylindrical casing, an inlet conduit for air under pressure communicating withv the casing adjacent the bottom thereof, a fire pot positioned in the lower end of the casing and spaced from the walls thereof,

said fire pot being open at its top and beingconduit connected with said air inlet conduit for supplying air for primary partial combustion to said nozzle, and a burned gas outlet conduit communicating with the upper part of the casing.

, 5. A burner comprising a vertical cylindrical casing, an inlet conduit for air under pressure communicating with the casing adjacent the bottom thereof, a fire pot positioned in the lower end of the casing and spaced from the walls thereof, said fire pot being open at its top and being formed with a central secondary air inlet opening in the bottom wall thereof and with its side wall curved to form an oblate spheroidal bowl, a substantially conical distributing deflector positioned centrally in the fire bowl, said deflector being spaced from the bottom wall to form an air inlet therebetween, spiral blades positioned in said inlet for whirling the secondary air about a vertical axis, a downwardly projecting fuel nozzle positioned at the upper end of the casing centrally thereof, a conduit connected with the air inlet conduit for supplying air for partial combustion to said nozzle, and a burned gas outlet conduit communicating with the upper part of the casing.

6. A burner comprising a vertical cylindrical casing, an inlet conduit for air under pressure communicating with the casing adjacent the bottom thereof, a fire pot positioned in the lower end of the casing and spaced from the walls thereof, said fire pot being open at its top and being formed with a central air inlet opening in the bottom wall thereof and with its side wall curved to form an oblate spheroidal bowl, a substantially conical deflector positioned centrally of the fire bowl, said deflector being spaced from the bottom wall to form an inlet therebetween, an enveloping shield positioned around the fire pot in closely spaced relation thereto and terminating adjacent the upper rim thereof so that the air passing to the secondary air inlet open- L ing passes over the outer wall of the fire pot, a

fuel nozzle centrally positioned at the upper end of the casing, a conduit connected with the air inlet conduit for supplying air for partial combustion to said nozzle, and a burned gas outlet conduit communicating with the upper part of the casing.

'7. In an oil burner having a vertical cylindrical casing,- means for supplying fuel, means for supplying air for primary partial combustion, ignition means, means for projecting the partial combustion products downwardly from the top of said casing along the axis thereof, a fire pot positioned at the bottom of the casing, said fire pot having an outer wall formed symmetrically about the axis of the casing and curved inwardly at its upper portion, and a deflector positioned near the bottom of the fire pot, said deflector being positioned axially of the casing and shaped to deflect the stream of partial combustion products horizontally and radially outwardly toward the curved wall of the fire pot, said fire pot being formed with a central secondary air inlet opening at the bottom thereof, said deflector being spaced above said opening to provide an air inlet whereby said secondary air is directed outwardly and radially in a substantially horizontal direction and whereby said air and the primary products of combustion impinge the curved wall of the flre pot to provide an intimate mixture.

8. In a liquid fuel burner the combination of a casing, an air inlet conduit communicating with the lower end of the casing, a fire pot positioned in the casing and spaced from the walls thereof, said fire pot being open at the top and being formed with a curved wall defining a bowl shaped vessel, a substantially conical deflector positioned centrally of the fire pot, said deflector being spaced from the bottom wall of the fire pot to form an opening therebetween, said fire pot being provided with an air inlet opening formed in the bottom thereof centrally beneath the deflector with which the said air inlet conduit communicates, a jacket surrounding said fire pot spaced therefrom and terminating near the upper part thereof whereby incoming air sweeps over the entire outer surface of the fire pot, a fuel nozzle centrally positioned at the upper end of the casing, aconduit connected with the said conduit for air under pressure communicating with the casing adjacent the bottom thereof, a flre pot positioned in the casing and spaced from the walls thereof, said flre pot being open at its top and being formed 'ith its side wall turned upwardly from the bott wall in a curve to form a bowl, a substantially conical deflector positioned centrally of the fire pot, said deflector being spaced from the bottom wall of the combustion chamber to form an opening therebetween, spiral bailles formed on the bottom of said deflector and positioned in said opening to give a rotating movement to the air stream about a vertical axis, the bottom of the combustion chamber being provided with an air inlet opening centrally thereof beneath the deflector, a Jacket surrounding said combustion chamber spaced therefrom and terminating near the upper rim thereof whereby incoming air sweeps over the entire outer surface of thel combustion chamber, a fuel nozzle centrally positioned at the upper end of the casing, a conduit connected with the air inlet conduit for supplying air for partial combustion to said nozzle, and a burned gas outlet bustle surrounding the upper portion of the casflnely divided fuel and a relatively small propor- M tion of air centrally into the combustion chamber against the top face of the conical baflle, means for igniting the fuel air mixture prior to delivery to the combustion chamber, and means for introducing a secondary air supply into the combustion chamber through the bottom aperture whereby upon striking the curved wall of the combustion chamber said secondary air supply is deflected and caused to whirl the partial combustion products of the fuel air mixture.

11. A burner comprising an oblate spheroidal shaped combustion chamber open at the top and provided with an aperture in the bottom centrally thereof, a circular baiile substantially conical on its top face positioned in axial alignment with the aperture in the combustion chamber and spaced from and overlapping the bottom aperture, spiral vaned deflectors located in the space between the baiiie and the bottom of the combustion chamber, means for injecting finely divided fuel mixed with a relatively small porportion of air centrally in the combustion chamber against the top face of the conical b'ailie, means for igniting the injected fuel air mixture prior to delivery to the combustion chamber, and means for introducing a secondary air supply into the combustion chamber through the bottom aperture and between the spiral vaned deflectors whereby the secondary air is given a rotary motion and whereby upon striking the curved wall' of the combustion chamber said secondary air is deflected. and caused to whirl in a vortex ring, the partial combustion products of the fuel air mixture uniting with the secondary air supply emerging from the underside of the baifle.

12. In a hydrocarbon burner having a combustion chamber, the combination of nozzle means for delivering fuel in a -flnely divided state, inlet means for introducing a limited air supply for partial combustion with said fuel, ignition means for the fuel and air mixture, gas conducting outlet means communicating with the upper portion of the combustion chamber, said nozzle means being positioned to direct the fuel into the combustion chamber, supply means for introducing secondary air for completing combustion into the combustion chamber, jacket means for cooling the external walls of the combustion chamber by the incoming secondary air, deflecting means for deflecting the mixture of fuel, primary air and partial combustion products v after entering the combustion chamber, additional deflecting means for deflecting the secondary air supply as it enters the combustion chamber in a direction substantially parallel to the flow of fuel, primary air and partial combustion products as directed by the flrst mentioned deflecting means, and means for giving the secondary air supply a spiral rotary motion as it enters the combustion chamber, said deflecting means being formed to bring the two deflected currents together, said combustion chamber being formed to direct the deflected currents of fuel and air in a whirling ring within the combustion chamber.

13. In a hydrocarbon burner operating with progressive combustion, the combination of a combustion chamber, said chamber having a large opening therein, burned gas outlet means communicating with said opening, nozzle means for atomizing fuel, mixing it with a limited primary air supply and injecting the mixture centrally through said opening into the combustion chamber, means for igniting the mixture, means for introducing a secondary air supply centrally into the combustion chamber whereby secondary and complete combustion takes place therein, baiiie means for deflecting radially the burning fuel and primary air mixture after it enters the combustion chamber, directing means for radially deflecting the secondary air supply as it enters the combustion chamber, said bailie means and directing means being formed and positioned to bring the deflected streams of burning fuel and primary air mixture and secondary air together immediately after they are deflected radially within the combustion chamber.

14. In a hydrocarbon burner operating with progressive combustion, the combination of a combustion chamber, said chamber having a large opening therein, burned gas outlet means communicating with said opening, nozzle means for atomizing fuel, mixing it with a limited primary air supply and injecting the mixture centrally through said opening into the combustion chamber, means for igniting the mixture, means for introducing a secondary air supply centrally into the combustion chamber whereby secondary and complete combustion takes place therein, baiile means for deflecting radially the burning fuel and primary air mixture after it enters the combustion chamber, and directing means for spirally deflecting the secondary air supply as it enters the combustion chamber, said baiile means and directing means being formed and positioned to bring the deflected streams of burning fuel and primary air mixture and secondary air together immediately after they are deflected radially within the combustion chamber.

EARL C. WALKER.