US4559009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aggregate dryer burner
Assignee: Hauck Manufacturing Inc
•
Filing: 1984-09-12
•
Granted: 1985-12-17
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Expires: 2004-09-12
Abstract
Abstract A swirl-type internal flame recirculation burner as used to fire asphalt plant aggregate dryers, air heaters and calcining kilns and method includes an atomizer assembly for swirling primary air in two concentric streams with the inner stream swirling more rapidly than the outer stream. Fuel oil is blast atomized in a continuous sheet into the inner stream without prefilming and then is shear atomized as the inner and outer streams violently intermix. The burning and swirling fuel and primary air mixture recirculates upstream along the burner axis. Secondary air is swirled in the same direction as the primary air and surrounds the primary air stream to promote further mixing and internal recirculation. A metal frustro-conical flame holder surrounds the burner head to stabilize and shape the recirculation flame and shield low-burn flames from tertiary air. The swirl of the secondary air is also adjusted to shape the flame. The burner may also be fired on gas or a combination of gas and oil.
Inventors
- 👤 John A. Marino
- 👤 Roderick G. Strohl, Jr.
- 👤 Robert B. Yost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:12
CPC Classifications
F; F23; F23D; F23D14/00; F23D14/20; F23D14/22; F23D14/24; F23D11/00; F23D11/10; F23D11/12; F23D11/14; F23D17/00; F23D17/002; F26; F26B; F26B23/00; F26B23/02
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
394 words
A burner including an axial fuel pipe; a fuel atomizer at the downstream end of the pipe; a primary air pipe coaxial with the fuel pipe, surrounding the fuel pipe and extending upstream from the fuel atomizer; a secondary air pipe coaxial with the fuel pipe, surrounding the primary air pipe and extending upstream from the atomizer; said secondary air pipe having an exit portion extending parallel to the axis of said fuel pipe; means for swirling primary air in a first direction; said means for swirling primary air including means adjacent said fuel atomizer defining two separate concentric swirl passages dividing the primary air into two flow masses, the first of said primary swirl passages configured to accelerate the flow of a first primary air mass therethrough in a swirling motion, the second of said primary swirl passages configured to impart a slower swirling motion to a second primary air mass flowing therethrough such that said second air mass flows faster axially than said first air massto thereby provide strong sheer atomization of fuel near said fuel atomizer upon engagement of the respective swirling air masses; the inner one of said separate concentric primary swirl passages having an exit portion diverging away from said atomizer and the outer of said primary swirl passages having an exit portion extending parallel to the axis of said fuel pipe; means for swirling secondary air in said first direction, said secondary air swirling means being adjustable to provide a varying degree of swirl in said secondary air; and a damper assembly joining the primary and secondary air pipes including an outer duct connected to said primary and secondary air pipes at an angle such that primary and secondary air respectively are directed with a minimum pressure drop to each respective primary and secondary swirling means, the duct having an upstream mouth adapted to be connected to a souce of combustion air, an interior wall dividing the duct into a primary air passage and a secondary air passage, both passages communicating with the upstream duct mouth, the primary air passage communicating with the primary air pipe, the secondary air passage communicating with the secondary air pipe, a first damper within the primary air passage to control the flow of primary air therethrough, a second damper within the secondary air passage to control the flow of secondary air therethrough.
Claim 2
Dependent Claim
394 words
A burner including an axial fuel pipe; a fuel atomizer at the downstream end of the pipe; a primary air pipe coaxial with the fuel pipe, surrounding the fuel pipe and extending upstream from the fuel atomizer; a secondary air pipe coaxial with the fuel pipe, surrounding the primary air pipe and extending upstream from the atomizer; said secondary air pipe having an exit portion extending parallel to the axis of said fuel pipe; means for swirling primary air in a first direction; said means for swirling primary air including means adjacent said fuel atomizer defining two separate concentric swirl passages dividing the primary air into two flow masses, the first of said primary swirl passages configured to accelerate the flow of a first primary air mass therethrough in a swirling motion, the second of said primary swirl passages configured to impart a slower swirling motion to a second primary air mass flowing therethrough such that said second air mass flows faster axially than said first air massto thereby provide strong sheer atomization of fuel near said fuel atomizer upon engagement of the respective swirling air masses; the inner one of said separate concentric primary swirl passages having an exit portion diverging away from said atomizer and the outer of said primary swirl passages having an exit portion extending parallel to the axis of said fuel pipe; means for swirling secondary air in said first direction, said secondary air swirling means being adjustable to provide a varying degree of swirl in said secondary air; and a damper assembly joining the primary and secondary air pipes including an outer duct connected to said primary and secondary air pipes at an angle such that primary and secondary air respectively are directed with a minimum pressure drop to each respective primary and secondary swirling means, the duct having an upstream mouth adapted to be connected to a souce of combustion air, an interior wall dividing the duct into a primary air passage and a secondary air passage, both passages communicating with the upstream duct mouth, the primary air passage communicating with the primary air pipe, the secondary air passage communicating with the secondary air pipe, a first damper within the primary air passage to control the flow of primary air therethrough, a second damper within the secondary air passage to control the flow of secondary air therethrough.
Claim 3
Dependent Claim
68 words
A burner as in claim 1 wherein the primary air pipe includes a larger diameter upstream section, a smaller diameter downstream section and a radially inward step joining said sections a distance upstream from the atomizer; and the secondary air pipe includes a larger diameter section, a smaller diameter section and a radially inward step joining said sections located downstream of the step in the primary air pipe.
Claim 4
Dependent Claim
68 words
A burner as in claim 2 including a gas pipe coaxial with the fuel pipe located between the primary and secondary air pipes, as inlet means joining the upstream end of the gas pipe and extending outwardly of the burner away from the damper assembly, said gas pipe including a radially inwardly extending step located between the radially inwardly extending steps in said primary and secondary air pipes.
Claim 5
Dependent Claim
59 words
A burner as in claim 2 including a plurality of secondary air swirl vanes located in the space between the steps in the primary and secondary air pipes and a gang ring operatively connected to said secondary air swirl vanes whereby movement of said ring simultaneously moves the vanes to vary the degree of swirl imparted to secondary air.
Claim 6
Dependent Claim
50 words
A burner as in claim 1 wherein said duct is rectangular in cross section, said interior wall extends between opposite sides of the duct to define rectangular primary and secondary air passages and the primary air passage is located on the side of the duct nearest said fuel pipe axis.
Claim 7
Dependent Claim
46 words
A burner as in claim 5 wherein the side of the duct farthest from said fuel pipe axis is oriented at approximately 135° to said axis and the side of the duct nearest said axis is oriented at an angle of approximately 45° to said axis.
Claim 8
Dependent Claim
54 words
A burner as in claim 1 including a frusto-conical flame holder and air deflector mounted on said secondary air pipe adjacent the downstream end thereof and extending downstream beyond the burner head, said flame holder and air deflector having a close fit with the secondary air pipe to limit the flow of air therebetween.
Claim 9
Dependent Claim
22 words
A burner as in claim 7 wherein the flame holder is axially adjustable and extends outwardly at an angle of approximately 25°.
Claim 10
Dependent Claim
31 words
A burner as in claim 1 wherein the angular change in direction of primary air flow between said primary air passage of said primary air pipe is not more than 45°.
Claim 11
Dependent Claim
31 words
A burner as in claim 9 wherein the angular change in direction of secondary air flow between said secondary air passage and said secondary air pipe is not more than 45°.
Claim 12
Dependent Claim
334 words
A swirl type burner comprising an axial atomizer having first swirl generating means for swirling an inner flow of primary air in a first direction, an oil delivery passage opening into the swirled first flow of air, second swirl generating means located outwardly and surrounding the first swirl generating means for swirling a second flow of primary air in said first direction, the downstream mouths of said first and second means being located adjacent to each other so that the swirled first and second flows are free to intermingle following discharge from the mouths to thereby provide strong sheer atomization of fuel near said atomizer; the mouth of said first swirl generating means having a portion diverging away from said atomizer and the mouth of said second swirl generating means having a portion extending parallel to the axis of said atomizer; outer swirl generating means surrounding said atomizer for swirling in said first direction a third flow of air comprising secondary air; said outer swirl generating means having a exit portion extending parallel to the axis of said atomizer; means for directing combustion air with a minimum loss in pressure to each of the first and second swirl generating means and to the outer swirl generating means; a gas delivery system including a gas pipe having an annular gas outlet located between the atomizer and the outer swirl generating means so that said system delivers gas between the swirling inner flows of primary air and the outer flow of secondary air, each of said atomizer, outer swirl generating means and gas delivery system having downstream ends defining a burner head; and a frustro-conical member surrounding the burner head and secured to the outer swirl generating means, said frusto-conical member including an outer air deflector surface extending from the outer swirl generating means a distance radially outwardly and axially downstream past the burner head for deflecting downstream flowing air from the burner heed and an inner surface for shaping the flame on the burner head.
Claim 13
Dependent Claim
334 words
A swirl type burner comprising an axial atomizer having first swirl generating means for swirling an inner flow of primary air in a first direction, an oil delivery passage opening into the swirled first flow of air, second swirl generating means located outwardly and surrounding the first swirl generating means for swirling a second flow of primary air in said first direction, the downstream mouths of said first and second means being located adjacent to each other so that the swirled first and second flows are free to intermingle following discharge from the mouths to thereby provide strong sheer atomization of fuel near said atomizer; the mouth of said first swirl generating means having a portion diverging away from said atomizer and the mouth of said second swirl generating means having a portion extending parallel to the axis of said atomizer; outer swirl generating means surrounding said atomizer for swirling in said first direction a third flow of air comprising secondary air; said outer swirl generating means having a exit portion extending parallel to the axis of said atomizer; means for directing combustion air with a minimum loss in pressure to each of the first and second swirl generating means and to the outer swirl generating means; a gas delivery system including a gas pipe having an annular gas outlet located between the atomizer and the outer swirl generating means so that said system delivers gas between the swirling inner flows of primary air and the outer flow of secondary air, each of said atomizer, outer swirl generating means and gas delivery system having downstream ends defining a burner head; and a frustro-conical member surrounding the burner head and secured to the outer swirl generating means, said frusto-conical member including an outer air deflector surface extending from the outer swirl generating means a distance radially outwardly and axially downstream past the burner head for deflecting downstream flowing air from the burner heed and an inner surface for shaping the flame on the burner head.
Claim 14
Dependent Claim
57 words
A burner as in claim 11 where the swirl number for the first swirl generating means is about 1.55, the swirl number for the second swirl generating means is about 0.96 and the swirl number for the outer swirl generating means is apprximately between 0.4 and 1.4 and the burner flame is of the internal recirculation type.
Claim 15
Dependent Claim
40 words
A burner as in claim 12 wherein the outer swirl generating means includes a set of adjustable radial swirl vanes and means ganging said vanes together for simultaneous movement to vary the swirl number of the outer swirl generating means.
Claim 16
Dependent Claim
48 words
A burner as in claim 13 including dampers controlling the flow of air to each of said swirl generating means, said dampers have opened and closed positions, said closed positions permitting sufficient air flow to the swirl means to maintain an internal recirculation gas flame at low burn.
Claim 17
Dependent Claim
256 words
A burner including an axial fuel pipe; a fuel atomizer at the downstream end of said fuel pipe; a primary air pipe coaxial with and surrounding said fuel pipe and extending upstream from said atomizer; a secondary air pipe coaxial with said fuel pipe, surrounding said primary air pipe and extending upstream from said atomizer; means adjacent to said atomizer for swirling primary air including means defining a first swirl passage and a second swirl passage, said first and second swirl passages being oriented concentrically relative to each other, each of said first and second swirl passages being configured to accelerate the primary air flowing respectively therethrough in a swirling motion in the same direction and at a different degree of swirl and in an axial direction at a different flow rate than the other said swirl passage, thereby to promote strong sheet atomization of fuel near said atomizer; the inner one of said primary swirl passages having an exit portion diverging away from said atomizer and the outer of said primary swirl passages having an exit portion extending parallel to the axis of said fuel pipe; means for swirling secondary air in the same direction as the swirling primary air flows, said secondary air swirling means being adjustable to provide a varying degree of swirl in said secondary air; said secondary airpipe having an exit portion extending parallel to the axis of said fuel pipe; and means for directing combustion air with a minimum loss in pressure to the respective primary and secondary swirling means.
Claim 18
Dependent Claim
256 words
A burner including an axial fuel pipe; a fuel atomizer at the downstream end of said fuel pipe; a primary air pipe coaxial with and surrounding said fuel pipe and extending upstream from said atomizer; a secondary air pipe coaxial with said fuel pipe, surrounding said primary air pipe and extending upstream from said atomizer; means adjacent to said atomizer for swirling primary air including means defining a first swirl passage and a second swirl passage, said first and second swirl passages being oriented concentrically relative to each other, each of said first and second swirl passages being configured to accelerate the primary air flowing respectively therethrough in a swirling motion in the same direction and at a different degree of swirl and in an axial direction at a different flow rate than the other said swirl passage, thereby to promote strong sheet atomization of fuel near said atomizer; the inner one of said primary swirl passages having an exit portion diverging away from said atomizer and the outer of said primary swirl passages having an exit portion extending parallel to the axis of said fuel pipe; means for swirling secondary air in the same direction as the swirling primary air flows, said secondary air swirling means being adjustable to provide a varying degree of swirl in said secondary air; said secondary airpipe having an exit portion extending parallel to the axis of said fuel pipe; and means for directing combustion air with a minimum loss in pressure to the respective primary and secondary swirling means.
Claim 19
Dependent Claim
236 words
A swirl type burner as in claim 15, wherein said secondary pipe includes an annular first diameter passage extending to the burner head, an annular second flow passage having a diameter larger than said first passage and extending upstream from the upstream end of the first passage; a radially inward stop joining the downstream end of the annular second flow passage with the upstream end of the annular first diameter passage, said step including an outer annular wall joining the outer walls of said passages and an inner annular wall joining the inner walls of said passages; and a swirl vane assembly at said step including a plurality of radial vanes positioned between said walls, each vane including a shaft rotatably extending through a bore in the outer step wall, said shafts being arranged in a circle on said wall, a pin extending from the outer end of each shaft, an annular adjustment ring surface thereof adjacent to each shaft, a link rotatably seated in each bore, each link having a cross bore with the pin from the adjacent shaft slideably extending through said cross bore, and adjustment ring lock means for freeing said annular adjustment ring for limited rotational movement to move all of said links relative to said shafts and thereby simultaneously rotate said radial vanes to vary the swirl of the flow and for locking the ring and vanes in a desired position.
Claim 20
Dependent Claim
41 words
A burner as in claim 16 wherein said inner wall includes an outwardly extending annular portion cooperating with said outer wall to define a radially inward flow path at the step, said vanes being positioned within said radially inward flow path.
Claim 21
Dependent Claim
52 words
A burner as in claim 16 wherein each of said vanes includes a portion extending from the shaft radially inwardly to substantially fill the space between said walls and a portion extending radially outwardly of the shaft to substantially fill the space therefrom to the outer wall of the second flow passage.
Claim 22
Dependent Claim
31 words
A burner as in claim 18 wherein said vanes are adjustable between 30° and 65° to a radial line extending from the axis of the individual pins to the burner axis.
Claim 23
Dependent Claim
19 words
A burner as in claim 16 wherein the swirl number for the assembly is between about 0.4 and 1.4.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |