US3439877A - Post-aerated gas jets - Google Patents

Post-aerated gas jets Download PDF

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Publication number
US3439877A
US3439877A US586832A US3439877DA US3439877A US 3439877 A US3439877 A US 3439877A US 586832 A US586832 A US 586832A US 3439877D A US3439877D A US 3439877DA US 3439877 A US3439877 A US 3439877A
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US
United States
Prior art keywords
flame
gas
slot
orifice
orifices
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US586832A
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English (en)
Inventor
John Hancock Leeds
Albert Westerman
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Geo Bray and Co Ltd
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Geo Bray and Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Geo Bray and Co Ltd filed Critical Geo Bray and Co Ltd
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Publication of US3439877A publication Critical patent/US3439877A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D99/00—Subject matter not provided for in other groups of this subclass
    • F23D99/002—Burners specially adapted for specific applications
    • F23D99/004—Burners specially adapted for specific applications for use in particular heating operations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2206/00—Burners for specific applications
    • F23D2206/0068—Gas burners for illumination with slot type nozzles

Definitions

  • This invention relates to a post-aerated jet for use with natural gas and other gases having similar combustion characteristics.
  • a well known type of post-aerated jet used for manufactured gas is the one having a flat, fan-shaped flame produced as a result of the impingement of two converging gas streams.
  • Such a jet is shown schematically in FIGURE 1 of the accompanying drawing.
  • the two shoulders, at either end of the major axis of the orifice, are the main feature, and cause two streams of gas to turn sharply and emerge from the two vertical and diametrically opposed parts of the orifice.
  • the two streams impinge upon each other and produce a flat fan-shaped flame at right angles to the major axis of the orifice.
  • the air required for combustion diffuses into the gas stream and its movement, because of the momentum of the gas stream and of the convection current produced by the flame, is largely in the direction of the flame. This air movement tends to lift the flame away from the orifice but is countered by the burning velocity of the flame which acts towards the orifice.
  • a balance is obtained between the upward velocities of the gas and air streams and the downward burning velocity of the flame, so that the flame is stable and sits on the orifice at the required operating pressure which is usually in the order of 1 /23 inches w.g.
  • the burning velocity of natural gas is, however, only about one quarter that of manufactured gas and the flame lifts at /2 inch w.g. pressure or less.
  • the present invention facilitates enhancement of the aforementioned counter current of air at the base of the flame, thereby producing a jet having a stable flame with natural gas at pressures of 1 /2-3 ins. water gauge.
  • a post-aerated jet for use with natural gas at operating pressures of l' /z3 inches water gauge includes in combination a hollow body portion of which one end is open and serves as a gas input whilst the other end is formed with a terminal portion provided with at least two closely spaced parallel slot orifices, said terminal portion also being formed with gas directing means for ensuring the emergence of a fan-shaped laminar gas stream at each orifice, said gas directing means being provided by the surfaces of at least one pair of inclined walls formed on the underside of said terminal portion and at either side of each of said slot orifices, each of said gas streams lying in a plane containing the major axis of its respective slot orifice, and the length of each of said slot orifices at right angles to the plane of its corresponding gas stream being small in comparison with the width of the said slot orifice.
  • Ignition of a natural gas flame is also a problem because of the tendency for an ignition flame situated some distance from the slot not to be transmitted to the stable region.
  • FIGURE 1 is a perspective view of the invention
  • FIGURE 2 is a sectional elevation of a gas jet taken in a plane perpendicular to the plane containing one of the slot orifices,
  • FIGURE 3 is a section of the jet shown in FIGURE 2 taken on the line AA,
  • FIGURE 4 is a sectional elevation of a gas jet taken in a plane perpendicular to the plane containing one of the slot orifices,
  • FIGURE 5 is a section of the jet shown in FIG. 4 taken on the line BB,
  • FIGURE 6 is a sectional elevation of a gas jet taken in a plane perpendicular to the plane containing one of the slot orifices,
  • FIGURE 7 is a section of the jet shown in FIG. 6 taken on the line C-C,
  • FIGURE 8 is a sectional elevation of a ribbon burner taken in a plane perpendicular to the plane containing one of the slot orifices,
  • FIGURE 9 is a section of the burner shown in FIG- URE 8 taken on the line DD.
  • FIGURE 2 shows the body portion 1 of the jet which may be made in ceramic or in metal and which is normally mounted in a holder having a means of attachment to a gas pipe.
  • Two parallel slot orifices 2 are formed in the upper wall of the body and break through into the internal cavity 3.
  • the shoulders 4 formed on either side of each slot orifice on the underside of the upper wall cause the gas entering the cavity 3 to converge towards each slot orifice and to impinge so that on emergence from the slot orifice two fan-shaped streams of gas are formed.
  • On ignition these coalesce to form a single flame the small stabilising portion of which develops in the stagnant region immediately above and between the two slot orifices.
  • the internal cavity 3 is wedge shaped with the major axis at right angles to the slots and, as shown in FIGURE 3, has two walls 5 which taper inwards slightly towards the triangular apex 6 of the cavity.
  • the slots 2 break through the upper wall of the cavity and the lower edges of the slot orifices are situated at a point below the junctions of the triangular faces of the apex 6 and the inwardly sloping walls 5.
  • a divergent or finger-like gas stream is formed by each fiat face of the underside of the slot orifice so that in this particular example four divergent gas-streams coalesce to form each major flame.
  • the degree of divergence can be controlled by the angular disposition of the faces relative to one another.
  • an angle between faces of 160 results in a flat, fan-shaped flame with only a slight depression in its upper perimeter, whereas an angle of 90 results in two separate flames with the point of divergence immediately above the orifice.
  • the lengths of the divergent flames can be controlled by the relative dimensions of the faces.
  • the two outer flames will be longer than the two inner ones.
  • the two inner flames can be made longer than the two outer ones.
  • the apex of the cavity may have more than two faces and the number of divergent flames depends on the number of faces exposed by the slot orifice at the point of breakthrough.
  • the stability of the flame can be controlled further by the distance between the two slots orifices, that is by varying the length of the stagnant region between the slot orifices. In some cases it may prove beneficial to use three slot orifices and hence have two stagnant zones.
  • jet there are two 0.004 in. wide slot orifices at 0.18 in. centres.
  • the included angle of the triangular apex is 150 and the included angle between one of these faces and one of the inwardly sloping walls is
  • the length ofeach of the faces of the triangular apex is 0.030 in. and the slot orifices extend down the inwardly sloping walls to a distance of 0.007 in.
  • the stability of the flame can be improved still further by situating the orifices at the base of a recess 7, as shown in FIGS. 4 and 5 the sides of which flare away from the ends of each orifice as described in more detail in co-pending application No. 1982/63. Flames which are stable above 4 ins. water gauge pressure are then obtained.
  • FIGS. 6 and 7 Another way of shrouding the base of the flame is shown in FIGS. 6 and 7.
  • the shroud which is in the form of a metal cup 8 is attached to a metal socket 9 formed on the jet.
  • the walls of the cup are of generally elliptical cross-section, and flare away from the ends of the slot orifices so that the plane containing the major axes of each elliptical cross-section is parallel to the planes containing each slot orifice.
  • Orifices 10 formed in the flared walls of the cup allow air to flow to the base of the flame appearing across the two slot orifices.
  • the stability of the flame is improved by air flowing over the rim of the cup, as shown by the arrows in FIG. 7, in reverse direction to that of the flame. This reverse air flow thereby inhibits flame lift.
  • FIGS. 8 and 9 in which orifices are provided in the ridge 11 of a continuous metal channel indicated generally at 12 with flames being formed at right angles to the channel.
  • pairs of orifices are formed in the ridge of the channel, the inside form of which is similar to that of the internal cavity 3 shown in FIGS. 2 and 3 of the accompanying drawing.
  • the pairs of orifices are arranged along the length of the channel at centres which allow air flow between the flame produced by each pair of orifices, and which are also such to allow interlighting of the flames one from another.
  • a post-aerated jet for use with natural gas at operating pressures of 1 /z3 inches water gauge including in combination a hollow body portion having a lower end which is open and serves as a gas input and an upper end which is formed with a terminal portion provided with at least two closely spaced parallel slot orifices, said terminal portion also being formed with gas directing means for ensuring the emergence of a fan-shaped laminar gas stream at each orifice, said gas directing means being provided by the surfaces of two pairs of inclined walls formed on the underside of said terminal portion and at either side of each of said slot orifices, each of said gas streams lying in a plane containing the major axis of its respective slot orifice, and the length of each of said slot orifices at right angles to the plane of its corresponding gas stream being small in comparison with the width the said slot orifice, said pairs of walls being positioned one above the other and sloping inwardly as they approach said upper end, the upper pair of said walls meeting in a line lying at right angles to the
  • a post-aerated jet according to claim 1 in which the portion of each of said surface exposed by its corresponding slot orifice produces a divergent laminar gas stream.
  • a post-aerated jet according to claim 2 in which the length of the exposed portion of each of said surfaces defines the length of its corresponding divergent gas stream.
  • a post-aerated jet according to claim 1 in which the 5 slot orifices are situated at the base of a recess the sides of which flare upwardly and away from the ends of each slot orifice.
  • a post-aerated jet according to claim 1 in which a cup-like member is mounted on the jet the walls of said member flaring away from the ends of each slot orifice.
  • a post-aerated jet according to claim 5 in which air inlet means are formed in the flared portion of said walls allowing air to flow to the base of the flame.
  • a gas burner including a plurality of aligned gas jets according to claim 1, said jets being provided in the ridge of a continuous channel-like member.

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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)
US586832A 1965-10-26 1966-10-14 Post-aerated gas jets Expired - Lifetime US3439877A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB45330/65A GB1133705A (en) 1965-10-26 1965-10-26 Post-aerated gas jets

Publications (1)

Publication Number Publication Date
US3439877A true US3439877A (en) 1969-04-22

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Application Number Title Priority Date Filing Date
US586832A Expired - Lifetime US3439877A (en) 1965-10-26 1966-10-14 Post-aerated gas jets

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US (1) US3439877A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
BE (1) BE688887A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE1529173B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1133705A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
NL (1) NL6615111A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3570771A (en) * 1968-12-27 1971-03-16 James R Richardson Gas burners

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES172978Y (es) * 1968-09-07 1972-12-16 Polidoro Quemador para llama de gas.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US50075A (en) * 1865-09-19 Improvement in gas-burners
US140164A (en) * 1873-06-24 Improvement in gas-burners
US692254A (en) * 1901-10-05 1902-02-04 Edward J Dolan Gas-burner.
FR500351A (fr) * 1918-10-14 1920-03-10 Pierre Trambouze Bec à gaz acétylène, à gaz de houille et autres gaz, pour l'éclairage et le chauffage
US1601863A (en) * 1923-12-12 1926-10-05 Milwaukee Gas Specialty Co Igniter tip and hood
US1631771A (en) * 1921-10-18 1927-06-07 Sheather Albert Oil burner
US2515845A (en) * 1946-06-25 1950-07-18 Shell Dev Flame pocket fluid fuel burner
US2573144A (en) * 1946-03-22 1951-10-30 Syncromatic Corp Slotted outlet gas burner head

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1289992A (en) * 1916-02-06 1918-12-31 Samuel Tully Willson Burner-head.
US1353217A (en) * 1918-07-11 1920-09-21 Charles C Chappelle Gas-burner
FR613811A (fr) * 1926-03-31 1926-11-30 J Et O G Pierson Perfectionnement aux rampes à gaz
AT113071B (de) * 1927-09-03 1929-04-25 Richard Bruenner Zeilenbrenner.
US2005801A (en) * 1931-08-17 1935-06-25 Garnet W Mckee Burner for various gases
US2840150A (en) * 1953-05-07 1958-06-24 Combustion Eng Gas burner of multi section port construction
FR1305269A (fr) * 1961-11-15 1962-09-28 Junkers & Co Brûleur à rangs de flammes

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US50075A (en) * 1865-09-19 Improvement in gas-burners
US140164A (en) * 1873-06-24 Improvement in gas-burners
US692254A (en) * 1901-10-05 1902-02-04 Edward J Dolan Gas-burner.
FR500351A (fr) * 1918-10-14 1920-03-10 Pierre Trambouze Bec à gaz acétylène, à gaz de houille et autres gaz, pour l'éclairage et le chauffage
US1631771A (en) * 1921-10-18 1927-06-07 Sheather Albert Oil burner
US1601863A (en) * 1923-12-12 1926-10-05 Milwaukee Gas Specialty Co Igniter tip and hood
US2573144A (en) * 1946-03-22 1951-10-30 Syncromatic Corp Slotted outlet gas burner head
US2515845A (en) * 1946-06-25 1950-07-18 Shell Dev Flame pocket fluid fuel burner

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3570771A (en) * 1968-12-27 1971-03-16 James R Richardson Gas burners

Also Published As

Publication number Publication date
GB1133705A (en) 1968-11-13
DE1529173B1 (de) 1970-12-17
NL6615111A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1967-04-27
BE688887A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1967-03-31

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