US3437322A - Air-heating gas burner - Google Patents

Air-heating gas burner Download PDF

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Publication number
US3437322A
US3437322A US559246A US3437322DA US3437322A US 3437322 A US3437322 A US 3437322A US 559246 A US559246 A US 559246A US 3437322D A US3437322D A US 3437322DA US 3437322 A US3437322 A US 3437322A
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United States
Prior art keywords
burner
air
flame
stream
chamber
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Expired - Lifetime
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US559246A
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English (en)
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John H Flynn
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Individual
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Individual
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/26—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid with provision for a retention flame
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/48—Nozzles
    • F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
    • F23D14/583—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration of elongated shape, e.g. slits
    • F23D14/586—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration of elongated shape, e.g. slits formed by a set of sheets, strips, ribbons or the like

Definitions

  • a burner installation located in an air stream to be heated has a burner casing with a flame surface to which lead main and pilot flame ports for flames directed downstream of the air stream.
  • the installation further provides a chamber surrounding the burner casing and having an outlet in line with the flame surface and spaced therefrom downstream of the air stream, as well as an inlet which faces upstream of the air stream, with the cross-sectional area of the inlet being so much smaller than that of the chamber that the latter serves as an expansion chamber substantially without any vacuumatic effect of the air passing therethrough on the flames.
  • This invention relates to gas burners in general, and to air-heating gas burners in particular.
  • the type of gas burner with which the present invention is concerned is a gas-fed flame burner installed within a directed utility stream of air or the like for heating the same, with the burner flame being directed downstream of the passing air.
  • Such burners are used as air heaters for all kinds of space heating especially, though not exclusively, in industrial establishments, and they are also used for other purposes such as heating large volumes of air or noncombustible gases in industrial processes, for example.
  • It is among the more important requirements of these heaters that for a burner in any installation the heat of the burner flame must flash the temperature of the passing air or gas to a usually high peak at maximum operational stream velocity. This requires, in turn, that the burner flame must maintain in the air or gas stream a zone of very high heat intensity.
  • Another important requirement of these heaters is flexibility in operation over a wide range, to the end of heating passing air or gas usually at full stream velocity to the same or different temperature peaks.
  • flame burners that would best meet the aforementioned requirements of these heaters are those of high-capacity flame performance which are supplied with a quantitatively regulatable combustible mixture of prefably fixed air-gas ratio for sustaining the flames without any outside or secondary air and, hence, produce flames of high heat-output at widely regulatable flame velocity or drive independent of the velocity of the passing air or gas stream.
  • the flame will, on regulation for maximum heat-output and drive, strike particularly deep into the passing stream beyond the burner and there maintain an extensive and highly heated zone which does not unduly heat the burner but in which the streaming air or gas will at even maximum velocity have some definite dwell and be in most intimate heat-exchange relation not only with the flame itself but also with its proclucts of combustion.
  • Another object of the present invention is to achieve in a flame burner the aforementioned shielding of the critical flame areas from the vacuum effects of the passing air or gas stream, by providing the burner at its flame side with a channel which is open downstream of the passing air or gas and of a depth to contain the pilot flames and the critical base area of the main flames, and continuously delivering to this channel secondary air or noncombustible gas at a volumetric flow rate at which it will prevent any flame-extinguishing vacuum formation at the critical flame areas by the passing air or gas stream to-be heated without, however, having any adverse effect on the stability of the flames at any setting of the latter.
  • a further object of the present invention is to provide a flame burner with the aforementioned channel in which the secondary air or gas is supplied by the passing stream to-be-heated by being simply diverted from the latter into the channel.
  • the hood in complemental sections, the same need not even be provided with air or gas admission openings and the latter may, instead, be provided by a gap between the mounted hood sections which advantageously faces upstream of the passing air or gas to-be-heated so that the admitted air or gas will have a maximum cooling effect on the burner.
  • the hood may advantageously be of general teardrop shape in cross-section with the narrow end forming the channel part, whereby the passing gaseous stream tobe-heated undergoes least turbulence and has reformed into a smooth-flowing stream when passing through the heat zone maintained by the burner flames.
  • the volumetric flow rate of secondary air or gas through the channel will prevent flameextinguishing vacuum formation at the critical flame areas without having any adverse effect on the stability of the flames at any setting of the latter.
  • FIG. 1 is a side view of a flame burner embodying the present invention
  • FIG. 2 is a section through the burner as taken on the line 2-2 of FIG. 1;
  • FIG. 3 is a cross-section through a burner embodying the invention in a modified manner.
  • the reference numeral designates a flame burner for heating a stream of air or other non-combustible gaseous matter, hereinafter referred to as air for brevity of expression.
  • the burner 10 is to this end suitably mounted, in this instance, within a duct 12 in which a stream of air flows in the direction of the arrows 14 past the burner in order to be heated by the burner flames F.
  • the burner 10 has a longitudinal burner casing 16 with an internal chamber 18 and main and pilot burner slots 20 and 22 which extend substantailly over the length of the casing 16.
  • the burner slots 20 and 22, which are provided in a flame surface 24 of the casing 16, are in communication with the chamber 18, with spaced restricted ducts 26 in the casing providing in this instance for communication between the chamber 18 and the pilot burner slots 22 (FIG. 2).
  • Arranged in the burner slots 20 and 22 are burner ribbon assemblies 28 and 30 which define main and pilot flame ports 32 and 34, respectively.
  • the casing chamber 18 is through a conduit 36 supplied with a combustible air-gas mixture which on ignition at the flame ports 32 and 34 sustains main or operating flames F and pilot flames p, respectively.
  • the burner casing 16 is in this instance symmetrical about a plane P in which the burner axis x lies and which intersects the flame surface 24 midway of its width (FIG. 2).
  • the burner described so far may be entirely conventional, and the same may be operated for high-capacity flame performance at which the air-gas mixture supplied to the chamber 18 will sustain the main and pilot flames F and p without any outside or secondary combustion air.
  • air and gas are premixed at a given ratio in a usual premixer (not shown) and the mixture conducted to the chamber 18 at widely variable volumetric flow rates for sustaining burner flames of correspondingly variable velocities or drive.
  • the air-gas ratio of the mixture is usually chosen for optimum heat-intensity of the flames, and the main flames F are at their maximum setting of particular high velocity or drive and also forward projection, but they would extinguish without pilot flames 12 since the rate at which the combustible mixture is fed to the main flames is usually greater than the rate of flame propagation.
  • the burner described so far were subjected in the duct 12 to an air stream at even one of the lower operational velocities of the latter in most any space-heating or other installation, the vacuum created in the vicinity of the flame surface 24 of the burner by the passing air would extinguish the pilot flames p and, hence, also the main flames F, and if such vacuum would perchance not extinguish the pilot flames p it may well extinguish the main flames F by interrupting them at their base 1). Accordingly, the burner described so far is of no avail for high-capacity flame performance in an air stream of most any operational velocity.
  • the present burner is by structurally simple and quite inexpensive conversion adapted for high-capacity flame performance in an air stream of most any, and even the highest, operational velocities.
  • this channel formation is part of a secondary chamber 50 which is preferably defined by a separate hood 52 over the burner casing 16.
  • the hood 52 has opposite end walls 54 and a peripheral wall 56,
  • its peripheral wall 56 has a part-cylindrical portion 58 and tangentially continuing planar portions 60, of which the part-cylindrical wall portion 58 rests against, and is at 62 secured to, the end flanges 42 of the burner casing 16, While the planar wall portions 60 converge toward, and define with the end walls 54, an opening 64 in the secondary chamber 50 which is in line with the flame ports 32, 34 and outwardly spaced from the flame surface 24 of the burner casing.
  • the end walls 54 of the hood 52 partly close the secondary chamber 50 at its opposite ends between the end flanges 42 of the burner casing 16 and the opening 64, while the end flanges 42 themselves close the remainder of the secondary chamber 50 at its ends (FIG. 2).
  • the end walls 54 of the hood 52 are in this instance parts of plates 66 which are separate from the peripheral hood wall 56 and conveniently clamped between the end flanges 42 of the burner casing and the covers 38 thereon, and the separate end walls 54 are in this instance further secured at 68 to outward flanges 70 at the opposite ends of the peripheral hood wall 56.
  • the part of the secondary chamber 50 between the flame surface 24 and opening 64 is in the form of a channel 72 which is open to the remaining part 74 of the chamber 50 at both sides 76 and 78 of the flame surface 24 (FIG. 2).
  • the depth of this channel part 72 of the secondary chamber 50 is in any event adequate to shield the critical flame areas of the burner directl from the passing air stream to-be-heated, and this channel depth is preferably only several times the maximum height of the pilot flames p as roughly shown (FIG. 2), so that virtually the entire main flames beyond their base b project at most operational settings beyond the opening 64 of the secondary chamber 50 and directly into the passing air stream to-be-heated.
  • the secondary air or non-combustible gas which is to flown through the channel part 72 of the secondary chamber 50 for preventing therein a flame-extinguishing vacuum formation by the passing air stream to-be-heated, is preferably and advantageously derived from the passing air stream itself.
  • the hood 52 is provided, preferably at the burner side opposite the flame surface 24, with a restricted slot 80 which extends over the longitudinal extent of the secondary chamber 50 and through which air from the passing stream is admitted into the latter.
  • the secondary chamber 50 serves as an expansion chamber in which the admitted air undergoes considerable reduction in pressure and velocity, and whatever turbulence the air may develop immediately on its admission into this expansion chamber will largely be pondered as it approaches the channel part 72 of this chamber, This makes for fairly smooth and moderate-velocity flow of the admitted air into and through the channel part 72 of this chamber and out through the opening 64 into the passing air stream, at which it will prevent at the critical flame areas of the burner any flame-extinguishing vacuum formation by the passing air stream to-be-heated without, however, adversely affecting the stability of the flames.
  • the converging planar wall portions 60 of the hood FIG.
  • the flow of the admitted air through this channel part is so smooth that it has been found advantageous to pass this flowing air into even closer proximity to the pilot flames p and the base b of the main flames F.
  • This is achieved in this instance by providing the converging wall portions 60 of the hood with baflles 82 which extend over the length of the channel part 72 and divert the passing secondary air generally over the flame surface 24.
  • the secondary air is thus flown toward the critical flame areas of the burner, and this is preferred in this specific or any other formation of the channel part 72, since the pilot flames then operate with particular assurance in a virtual non-vacuum zone under all conditions and, hence, support and keep ignited the main flames from minimum to maximum heat output.
  • baffles 82 in this preferred channel construction are suitably secured by exemplary screws 84 to the converging hood walls 60. Also secured by some of the same screws 84 to the peripheral hood wall 56 are spacer brackets 86 of exemplary V- shape which rest against the burner casing 16 and afford the hood additional support on the latter. Admission of the secondary air into the secondary chamber 50 through the slot 80 also makes for maximum cooling of the burner casing 16 and exit end 64 of the chamber by this secondary air.
  • the hood 52 and in this instance its peripheral wall 56, is preferably and advantageously formed in two identical complemental sections 88 and 90 which are provided with longitudinal flanges 92 that are kept spaced to define the described slot 80 for admission of the secondary air, with these flanges 92 having to this end interposed spacers 94 that are held in place by bolts 96 which additionally lock the mounted sections 88 and to each other.
  • the peripheral hood wall 56 is with its converging planar wall parts 60 so disposed that the secondary chamber 50 is in cross-section also symmetrical about the plane of symmetry P of the burner casing 16 (FIG. 2), whereby the flow of secondary air to the channel part 72 is evenly divided on the opposite sides 76 and 78 of the flame surface 24.
  • the hood 52 is in cross-section of teardrop-like shape (FIG. 2) which offers comparatively little resistance to the passing air stream to-be-heated, with the passing air having at the hood opening 64 largely reformed into a smooth-flowing stream which does not adversely affect the stability of the main flames F at any, including their maximum, drive and, hence, projection from the hood opening 64, and is in intimate heat-exchange relation with the main flames as well as with their products of combustion over the high-intensity heat zone of daunting extent maintained by these flames.
  • FIG. 2 teardrop-like shape
  • FIG. 3 shows a modified air-heating flame burner 10a that differs from the described burner 10 of FIGS. 1 and 2 primarily by having a secondary chamber 50a which is of smaller size and volume and also surrounds only part of the burner casing 16a.
  • the hood 52a may in most respects be constructed like the described hood 52, except that the part-cylindrical portion 58a of the peripheral hood wall 56a extends between the end flanges 42a of the burner casing 16a and bears against the side of the casing opposite the flame surface 24a thereof to divide the part 74a of the secondary chamber 50a into non-communicating sections 100 and 102 which are, however, in communication with the channel part 72a of the secondary chamber at opposite sides of the flame surface 24a of the burner casing.
  • the part-cylindrical portion 58a of the peripheral hood wall 56a has at its opposite ends leg formations 104 by which it is mounted on the end flanges 42a of the burner casing.
  • Air from the passing stream to-be-heated is admitted into the chamber sections 100 and 102 through longitudinal openings 106 which are formed in the peripheral hood wall 56a preferably by striking therefrom baffles 108 which direct air from the passing stream into the openings 106 and, hence, into the secondary chamber 50a.
  • a burner adapted for installation in a conduit for a gaseous stream to-be-heated comprising a longitudinal burner casing having a flame surface facing upstream of the stream and main and pilot flame ports leading to said flame surface; and a longitudinal chamber with opposite end walls and an inner peripheral surface surrounding said casing over its longitudinal extent and spaced therefrom over at least the greater part of the circumference of the casing including said flame surface, said chamber having a longitudinal outlet in line with said flame surface and spaced therefrom downstream of the stream, and longitudinal inlet means facing upstream of the stream and being in comparison to the space between said casing and peripheral wall surface of said chamber of such restricted cross-sectional area that said space acts as an expansion chamber in which admitted gas from the stream has substantially no vacuum effect and said inner peripheral surface of said chamber has on opposite sides of said flame surface baffle portions for directing passing gas toward said flame ports.
  • a burner adapted for installation in a conduit for a gaseous stream to-be-heated comprising a longitudinal burner casing having a flame surface facing downstream of the stream, and an internal chamber and therewith communicating main and pilot flame ports of which said ports lead to said flame surface; and a hood surrounding said casing and having end walls and a peripheral wall defining another chamber with an opening in line with said ports and spaced from said flame surface downstream of the stream, of which the part of said other chamber between said flame surface and opening is in the form of a channel open to the remaining chamber part on both sides of said flame surface; and port means in said remaining chamber part facing upstream of the stream and being in comparison to the space between said casing and peripheral wall of said other chamber of such restricted cross-sectional area that said space acts as an expansion chamber in which admitted gas from the stream has substantially no vacuum effect, and said peripheral hood wall rests against said casing on the side thereof opposite said flame surface to divide said remaining chamber part into non-communicating chamber sections of which each is provided with said port means.
  • a burner adapted for installation in a conduit for a gaseous stream to-be-heated comprising a longitudinal burner casing having a flame surface facing downstream of the stream, and an internal chamber and therewith communicating main and pilot flame ports of which said ports lead to said flame surface; and a hood surrounding said casing and having end walls and a peripheral wall defining another chamber with an opening in line with said ports and spaced from said flame surface downstream of the stream, of which the part of said other chamber between said flame surface and opening is in the form of a channel open to the remaining chamber part on both sides of said flame surface, and said peripheral hood wall has a part-cylindrical section and tangentially continuing plane sections to and converging on said opening, so that said hood is a teardrop-like shape in cross-section; and port means in said remaining chamber part facing upstream of the stream and being in comparison to the space between said casing and peripheral wall of said other chamber of such restricted cr0ss-sectional area that said space acts as an expansion chamber in which admitted gas from the stream
  • a burner as in claim 4 in which said casing has annular end flanges forming parts of said end hood walls, and said part-cylindrical section of said peripheral hood wall rests on and is secured to said end flanges.
  • a burner as in claim 4 in which said plane wall sections are provided within said channel part with longitudinal baflies for diverting a gaseous medium flowing from said remaining chamber part into said channel part toward said flame surface.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Gas Burners (AREA)
US559246A 1966-06-21 1966-06-21 Air-heating gas burner Expired - Lifetime US3437322A (en)

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US55924666A 1966-06-21 1966-06-21

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US3437322A true US3437322A (en) 1969-04-08

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JP (1) JPS5434941B1 (de)
DE (1) DE1551783B2 (de)
GB (1) GB1118039A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3494711A (en) * 1968-06-28 1970-02-10 Eclipse Fuel Eng Co Burner for heating a gaseous medium having a low oxygen content
US3494712A (en) * 1968-07-01 1970-02-10 Coen Co Duct burner
US4042317A (en) * 1975-11-10 1977-08-16 Flynn Burner Corporation Direct flame apparatus for drying can coatings
US4432727A (en) * 1982-09-21 1984-02-21 Joseph Fraioli Gas-fired infrared projection heater
US4507083A (en) * 1982-09-21 1985-03-26 Joseph Fraioli Gas-fired infrared projection heater
US4549866A (en) * 1984-05-08 1985-10-29 Flynn Burner Corporation Method and apparatus for applying heat to articles and materials

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT201700106691A1 (it) * 2017-09-25 2019-03-25 I C I Caldaie S P A Caldaia.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1729149A (en) * 1923-07-23 1929-09-24 Gen Electric Gas burner
US2196829A (en) * 1938-03-05 1940-04-09 Selas Company Air heater
US3055145A (en) * 1959-05-18 1962-09-25 Maurice E Lindsay Air distributing and tempering machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1729149A (en) * 1923-07-23 1929-09-24 Gen Electric Gas burner
US2196829A (en) * 1938-03-05 1940-04-09 Selas Company Air heater
US3055145A (en) * 1959-05-18 1962-09-25 Maurice E Lindsay Air distributing and tempering machine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3494711A (en) * 1968-06-28 1970-02-10 Eclipse Fuel Eng Co Burner for heating a gaseous medium having a low oxygen content
US3494712A (en) * 1968-07-01 1970-02-10 Coen Co Duct burner
US4042317A (en) * 1975-11-10 1977-08-16 Flynn Burner Corporation Direct flame apparatus for drying can coatings
US4432727A (en) * 1982-09-21 1984-02-21 Joseph Fraioli Gas-fired infrared projection heater
US4507083A (en) * 1982-09-21 1985-03-26 Joseph Fraioli Gas-fired infrared projection heater
US4549866A (en) * 1984-05-08 1985-10-29 Flynn Burner Corporation Method and apparatus for applying heat to articles and materials

Also Published As

Publication number Publication date
JPS5434941B1 (de) 1979-10-30
DE1551783B2 (de) 1976-08-05
GB1118039A (en) 1968-06-26
DE1551783A1 (de) 1970-04-02

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