US3551085A - Burner for fluid fuels - Google Patents

Burner for fluid fuels Download PDF

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Publication number
US3551085A
US3551085A US767339A US3551085DA US3551085A US 3551085 A US3551085 A US 3551085A US 767339 A US767339 A US 767339A US 3551085D A US3551085D A US 3551085DA US 3551085 A US3551085 A US 3551085A
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US
United States
Prior art keywords
fuel
burner
combustion air
combustion
fuel chamber
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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
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US767339A
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English (en)
Inventor
Denis Henry Desty
David Montagu Whitehead
John Lionel Thomas
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BP PLC
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BP PLC
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Filing date
Publication date
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Publication of US3551085A publication Critical patent/US3551085A/en
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Classifications

    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D17/00—Burners for combustion conjointly or alternatively of gaseous or liquid or pulverulent fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
    • F23D2900/00012—Liquid or gas fuel burners with flames spread over a flat surface, either premix or non-premix type, e.g. "Flächenbrenner"

Definitions

  • a burner for fluid fuels comprises a plurality of com bustion air tubes which pass through a. fuel chamber.
  • the tubes connect with the fuel chamber so that, during use, fuel enters the air flowing in the combustion air tubes.
  • the fuel flow is a curtain close to the wall so that burning takes place close to the wall.
  • Suitable ducts e.g. annular ducts, achieve this.
  • the outlet ends of the combustion air tubes form a heat exchanger.
  • This invention relates to a burner suitable for use with fluid fuels and particularly to a burner which can conveniently be combined with equipment such as heat exchangers which require a heat source.
  • a burner for fluid fuels comprises a plurality of combustion air tubes which pass through a fuel chamber, the bore of "each combustion air tube being connected with the fuel chamber in such a manner that, in the use of the burner, fuel passes from the fuel chamber into the air flowing in the combustion air tubes.
  • each combustion air tube has a cylindrical or venturi configuration.
  • connection between the bores of the combustion air tubes and the fuel chamber is such that fuel enters the combustion air tubes in such a manner that it remains adjacent to the walls and burns as a diffusion flame.
  • This can be achieved either by the use of suitably directed ducts or by exploitation of the skin effect.
  • the bores of the combustion air tubes are connected to the fuel chamber via ducts parallel to the walls of the combustion air tubes, e.g. annular ducts.
  • the skin effect relates to the tendency of a fluid flowing over a surface to stick to the surface, i.e. the flow will follow a suitably shaped convex surface.
  • Coanda nozzles exploit the skin effect and they are particularly suitable for use in burners according to the invention.
  • a Coanda nozzle comprises a series of facets (arranged so that the internal surface of the combustion air tube becomes the last facet). The facets form a convex surface and during use the fuel flow sticks to this surface so that when it enters the combustion air tube it stays close to the wall.
  • a Coanda nozzle also assists aspiration by aerodynamic effects. Venturi configurations for the combustion air tubes are particularly suitable for exploiting these effects.
  • the burners according to the invention may operate on both gaseous and liquid fuels.
  • the connection between the bores of the combustion air tubes and the fuel chamber should provide a resistance to fuel flow which is high in comparison with the resistance of the fuel chamber (i.e. the interstitial space between the tubes).
  • This combination of low resistance followed by high resistance en- Patented Dec. 29, 1970 ice coliglrages uniform flow of fuel into the combustion air tu es.
  • the burner is preferably provided with a control device which maintains a working level of liquid in the fuel chamber which is at or close to the connection between the fuel chamber and the bores of the combustion air tubes.
  • the control device may take the form of either a constant level or a constant flow device (which is adjustable to provide both low and high thermal outputs).
  • the invention also includes a combustion device in which the outlet ends of the combustion air tubes of a burner as described above pass through a heat absorbing zone, e.g. heat exchanger, whereby, during the use of the burner, heat derived from the combustion of the fuel is passed into the heat absorbing zone.
  • a heat absorbing zone e.g. heat exchanger
  • a preferred embodiment of a combustion device as described above comprises a fuel chamber situated adjacent to a heat exchanger chamber and a plurality of combustion air tubes which pass through the fuel chamber and the heat exchanger chamber; the bore of each combustion air tube being connected with the interior of the fuel chamber in such a manner that, during the use of the device, fuel passes from the fuel chamber into the bores of the combustion air tubes and the heat produced by the combustion therein is transferred to a heat exchange medium, e.g. water or air, circulated through the heat exchanger chamber.
  • a heat exchange medium e.g. water or air
  • FIG. 1 is a diagrammatic perspective view with part cut-away of a burner according to the invention
  • FIG. 2 is a vertical cross-section of a portion of the burner shown in FIG. 1 to an enlarged scale
  • FIG. 3 is a horizontal cross-section on the line 33 of FIG. 2, and
  • FIG. 4 is a vertical cross-section, similar to FIG. 3, of a burner/heat exchanger combination in accordance with the invention.
  • the overall appearance of the burner is a rectangular box 10 with a matrix of combustion air tubes 11 which are sealed into an outlet plate 12 and an inlet plate 13.
  • each combustion air tube comprises an upper portion 14 whose lower end fits outside the upper end of a lower portion 15 thereby forming an annular duct 16.
  • the arrangement of the annular ducts and the hexagonal pattern of the combustion air tubes is also illustrated in the horizontal cross-section of FIG. 3.
  • the fuel passes through the interstitial space 17 between the combustion air tubes. It enters the bores of the combustion air tubes via the annular ducts 16 and flows as a curtain of fuel adjacent to the walls of the tubes where combustion takes place as a silent diffusion flame.
  • annular ducts 16 collectively provide a high resistance path for the fuel whereas the interstitial space 17 provides a low resistance. This arrangement encourages even flow of fuel into the combustion air tubes.
  • annular ducts 16 In the case of a liquid fuel burner the annular ducts 16 have a lower resistance and the burner is fitted with a control device which maintains a level of fuel within the annular ducts. The fuel within the annular ducts is exposed to the radiant heat of combustion which vaporises it into the combustion zone.
  • the control may be achieved either by an adjustable constant level device or an adjustable constant flow device.
  • a constant level device the higher the level the greater the heat transfer to the liquid and hence the greater the rate of vaporisation and therefore the greater the heat output.
  • the level adjusts itself until the rate of vaporisation balances the flow rate. In both cases it is desirable to provide an over-ride to prevent the burner flooding at too high a setting or going out at too low a setting.
  • FIG. 4 shows a burner as illustrated in FIGS. 1-3 which is combined with a heat exchanger.
  • the combustion air tubes continue to a top plate 18 instead of terminating at the outlet plate 12. This forms a chamber in which water or air can be circulated through the interstitial space 19.
  • This arrangement forms a compact and efficient burner/ heat exchanger combination since the heat generated by the combustion within the upper portions 14 of the combustion air tubes is transferred to the water or air circulated through the interstitial space 19.
  • the overall external dimensions of the prototype were 6 cm. square by 1.5 cm. deep although the combustion air tubes were situated in a centre rectangle 4.2 cm. x 3.5 cm. (i.e. the true burner dimensions were 4.2 cm. x 3.5 cm. x 1.5 cm. deep).
  • the prototype comprised 25 combustion air tubes 6 mm. in diameter at the outlet end and mm. in diameter at the inlet end. Each tube had an annular inlet (of gap 0.1 mm. and length 3 mm.) whose opening into the tube was about half way along.
  • the interior of the burner was divided into a heat exchanger space and a fuel space of equal volume by a centre partition.
  • the heat exchanger surface area was 28.3 cm.
  • the prototype was operated on town gas (50% H 30% CH, and rest inert) under a 25 cm. chimney. Burning was by small ring-shaped flames which remained within the combustion air tubes close to the walls.
  • -A combustion device which comprises a fuel chamber, a heat exchanger chamber and a plurality of compassage for admixture with combustion air flowing therethrough, whereby, when fuel is fed into the fuel chamber and a heat exchange medium is circulated through the heat exchangerchamber, fuel passes from the fuel chamber into air flowing in said passages of the combustion air tube means and the heat produced by the combustion therein is transferred to the heat exchange medium.
  • a burner for fluid fuels comprising a fuel chamber, a plurality of combustion air tube means through which air will pass positioned within said fuel chamber and extending therethrough in substantially transverse relationship to the'long axis of said chamber, each of said air tube means forming a single passage through said fuel chamber and having fuel inlet means intermediate the ends thereof and within said fuel chamber for passing fuel from said fuel chamber into said passage for admixture with combustion air flowing therethrough.
  • each of said combustion air tube means includes an upper tube portion having a free end portion and a lower tube portion having a free end portion with the respective free end portions of each being in axially enveloping and laterally spaced relationship with one another and forming an annular inlet passageway therebetween through which fuel willpassfrom the fuel chamber into said single passage for admixture with combustion air flowing therethrough.
  • said fuel chamber includes opposed plate members spaced from one another in generally parallel relationship, one end of each of said tube means fixed in one of said plate members, with the opposite end of each of said tube means fixed in the other of said plate members.
  • each said combustion air tube means includes an upper tube portion having a free end portion terminating within said fuel chamber and a lower tube portion having a free end portion terminating within said fuel chamber, said free end portions of each of said combustion air tube means being in axially enveloping and laterally spaced relationship with one another and forming an annular fuel inlet passageway within the fuel chamber through which fuel will pass from the fuel chamber into said single passage for admixture with combustion air flowing therethrough.
  • each combustion air tube means is cylindrical.
  • cal/min i.e. a thermal efficiency of 24% and a heat flux of cals/cm lmin.
  • the thermal output can be increased by using m1 tubes (of the same diameter) and the thermal efficiency can b increased by increasing the length of the tubes (i.e. the heai exchanger surface area).

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Of Fluid Fuel (AREA)
  • Pressure-Spray And Ultrasonic-Wave- Spray Burners (AREA)
  • Gas Burners (AREA)
US767339A 1967-10-26 1968-10-14 Burner for fluid fuels Expired - Lifetime US3551085A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4876267 1967-10-26

Publications (1)

Publication Number Publication Date
US3551085A true US3551085A (en) 1970-12-29

Family

ID=10449818

Family Applications (1)

Application Number Title Priority Date Filing Date
US767339A Expired - Lifetime US3551085A (en) 1967-10-26 1968-10-14 Burner for fluid fuels

Country Status (8)

Country Link
US (1) US3551085A (xx)
AT (1) AT290067B (xx)
BE (1) BE722925A (xx)
CH (1) CH487371A (xx)
DE (1) DE1804798A1 (xx)
FR (1) FR1588708A (xx)
GB (1) GB1227347A (xx)
NL (1) NL6814653A (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3681000A (en) * 1970-09-17 1972-08-01 Dunlop Holdings Ltd Burners
JPS51125351U (xx) * 1975-07-30 1976-10-09
US4887963A (en) * 1988-03-21 1989-12-19 Chaffoteaux Et Maury Gas burners
US4909728A (en) * 1986-09-26 1990-03-20 Matsushita Electric Industrial Co., Ltd. Combustion apparatus
US5438834A (en) * 1992-12-24 1995-08-08 Societe Europeenne De Propulsion Close combustion gas generator
US20170115000A1 (en) * 2014-06-13 2017-04-27 Karen Meyer Bertram Systems, apparatus, and methods for treating waste materials

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL168605C (nl) * 1972-04-17 1982-04-16 Radiation Ltd Warmteuitwisselingssamenstel.
DE8710017U1 (de) * 1987-07-22 1988-11-24 Viessmann Werke GmbH & Co, 3559 Allendorf Gasbrennvorrichtung für Heizkessel, Heißwassererzeuger od.dgl.

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3681000A (en) * 1970-09-17 1972-08-01 Dunlop Holdings Ltd Burners
JPS51125351U (xx) * 1975-07-30 1976-10-09
JPS5430190Y2 (xx) * 1975-07-30 1979-09-22
US4909728A (en) * 1986-09-26 1990-03-20 Matsushita Electric Industrial Co., Ltd. Combustion apparatus
US4887963A (en) * 1988-03-21 1989-12-19 Chaffoteaux Et Maury Gas burners
US5438834A (en) * 1992-12-24 1995-08-08 Societe Europeenne De Propulsion Close combustion gas generator
US20170115000A1 (en) * 2014-06-13 2017-04-27 Karen Meyer Bertram Systems, apparatus, and methods for treating waste materials
US10612778B2 (en) * 2014-06-13 2020-04-07 Karen Meyer Bertram Systems, apparatus, and methods for treating waste materials

Also Published As

Publication number Publication date
BE722925A (xx) 1969-04-25
CH487371A (de) 1970-03-15
AT290067B (de) 1971-05-25
GB1227347A (xx) 1971-04-07
DE1804798A1 (de) 1969-05-08
FR1588708A (xx) 1970-04-17
NL6814653A (xx) 1969-04-29

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