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US4157889A Expired / Lapsed US ⏱️ 0.0 years remaining

Burner for powdered fuel

Assignee: Colmant Cuvelier SA
•
Filing: 1977-04-13
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Granted: 1979-06-12
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Expires: 1997-04-13
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Abstract

Abstract The invention comprehends a burner for powdered fuel comprising an annular conduit for the injection of solid fuel in powder form, included between two coaxial conduits for the injection of air, one internal and the other external in which the three conduits discharge into an expansion and stabilization chamber which is formed by a divergent truncated portion connected to the external air injection conduit and which also has a central cylindrical portion and a terminal convergent truncated portion.

Inventors

  • 👤 Michel G. Bonnel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 04:47
CPC Classifications
F; F23; F23D; F23D1/00; F23D17/00; F23D17/007

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 129 words
A burner for powdered fuel comprising an annular conduit for the injection of solid fuel in powder from entrained in air, a first conduit coaxial with and internal to said annular conduit and a second conduit coaxial with and external to said annular conduit, each of said first and second conduits having air supplied thereto, means forming a chamber, each of said three conduits having an end for discharging the flow therefrom into said chamber where the flows are mixed, means at the discharge end of said annular conduit for producing a substantially laminar or somewhat convergent flow of the fuel into said chamber, and means at the respective discharge ends of each of said first and second conduits for producing a vortex flow of air into said chamber.
Claim 2
Dependent Claim 129 words
A burner for powdered fuel comprising an annular conduit for the injection of solid fuel in powder from entrained in air, a first conduit coaxial with and internal to said annular conduit and a second conduit coaxial with and external to said annular conduit, each of said first and second conduits having air supplied thereto, means forming a chamber, each of said three conduits having an end for discharging the flow therefrom into said chamber where the flows are mixed, means at the discharge end of said annular conduit for producing a substantially laminar or somewhat convergent flow of the fuel into said chamber, and means at the respective discharge ends of each of said first and second conduits for producing a vortex flow of air into said chamber.
Claim 3
Dependent Claim 67 words
A burner as in claim 1 wherein said means forming said chamber comprises a diverging truncated conical section connected to the discharge end of said second conduit, a cylindrical central section and a terminal converging truncated conical section, the air from said second conduit being rotated by the walls of the chamber and reflected back toward the end of the annular conduit by the terminal converging section.
Claim 4
Dependent Claim 29 words
A burner according to claim 1 wherein the means at the end of the annular conduit for the injection of fuel in suspension in air produces a convergent flow.
Claim 5
Dependent Claim 43 words
A burner according to claim 1 wherein the means at the respective ends of said first and second air injection conduits comprise vanes of inverse pitch so that the central flow of fuel in suspension is arranged between two vortices of inverse sense.
Claim 6
Dependent Claim 52 words
A burner according to claim 1 wherein the annular conduit comprises a straight line section discharging into the expansion chamber and a plurality of convergent oblique conduits symmetrical with respect to the axis of the burner supplying fuel to said straight line section such that the flow of primary air is laminar.
Claim 7
Dependent Claim 31 words
A burner according to claim 1 further comprising a spiral chamber for said second conduit to increase the degree of whirling movement of the said air flow from the second conduit.
Claim 8
Dependent Claim 44 words
A burner according to claim 1 wherein the end of the first conduit discharges into said chamber in a plane situated downstream of the plane in which are situated the discharge end of the annular conduit and the discharge end of the first conduit.
Claim 9
Dependent Claim 35 words
A burner as in claim 2 further comprising a third conduit for liquid fuel for ignition of the powder fuel, said third conduit being coaxial with and interior of the first conduit and movable therewith.
Claim 10
Dependent Claim 25 words
A burner according to claim 1 further comprising a variable speed and volume blower means for controlling the flow of air transporting the powdered fuel.
Claim 11
Dependent Claim 36 words
A burner according to claim 1 further comprising means for controlling the quantity of air discharged into the chamber by the first conduit to be greater than the quantity of air discharged by the second conduit.
Claim 12
Dependent Claim 31 words
A burner according to claim 10 in which the total quantity of discharged air is divided in the ratio of 2/3 in the first conduit and 1/3 in the second conduit.
Claim 13
Dependent Claim 32 words
A burner according to claim 1 further comprising a third conduit for liquid fuel for ignition of the powder fuel, said third conduit being coaxial with and interior of the first conduit.
Claim 14
Dependent Claim 39 words
A burner according to claim 12 further comprising valve means for the second conduit which is closed when the conduit for the ignition liquid fuel is being supplied, so that only air from the internal first conduit is supplied.
Claim 15
Dependent Claim 124 words
A burner for powdered fuel comprising an annular conduit for the injection of solid fuel in powder form entrained in an air stream, a first conduit coaxial with and internal to said annular conduit and a second conduit coaxial with and external to said annular conduit, each of said first and second conduits having air supplied thereto, means forming a chamber, each of said three conduits having an end for discharging the flow therefrom into said chamber, said means forming said chamber including a divergent truncated portion connected to the end of said second conduit, a central cylindrical portion and a terminal converging portion, said end of said annular conduit being convergent, and located between the ends of said first and said second conduits.
Claim 16
Dependent Claim 124 words
A burner for powdered fuel comprising an annular conduit for the injection of solid fuel in powder form entrained in an air stream, a first conduit coaxial with and internal to said annular conduit and a second conduit coaxial with and external to said annular conduit, each of said first and second conduits having air supplied thereto, means forming a chamber, each of said three conduits having an end for discharging the flow therefrom into said chamber, said means forming said chamber including a divergent truncated portion connected to the end of said second conduit, a central cylindrical portion and a terminal converging portion, said end of said annular conduit being convergent, and located between the ends of said first and said second conduits.
Claim 17
Dependent Claim 33 words
A burner as in claim 14 further comprising means for moving said annular and said first conduits longitudinally relative to each other to control the flow of air fuel from said annular conduit.
Claim 18
Dependent Claim 30 words
A burner according to claim 15 wherein the diverging slope of the wall of the first conduit is greater than the converging slope of the wall of the annular conduit.
Claim 19
Dependent Claim 32 words
A burner according to claim 16 in which the divergent portion of the first conduit is extended by a cylindrical portion the extremity of which constitutes the extremity of the first conduit.
Claim 20
Dependent Claim 26 words
A burner according to claim 17 in which the length of the said cylindrical portion is determined in accordance with desired combustion characteristics of the burner.
Claim 21
Dependent Claim 29 words
A burner according to claim 15 in which the length of the central cylindrical portion of the chamber is determined in accordance with desired combustion characteristics of the burner.
Claim 22
Dependent Claim 30 words
A burner according to claim 15 in which the dimensions of the terminal truncated convergent portion of the chamber are determined in accordance with desired combustion characteristics of the burner.
Claim 23
Dependent Claim 23 words
A burner according to claim 14 wherein the annular conduit supplied with the powdered fuel by fluidizing the fuel in an air stream.
Claim 24
Dependent Claim 14 words
A burner according to claim 21 in which the fluidizing air is hot air.

References Cited (Backward Citations)

GB298080A Cited
GB308054A Cited
GB323578A Cited
US2921542A Cited
US3049085A Cited
US3147795A Cited
US3729285A Cited
US3915387A Cited
US3894834A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-06-11 1982-12-11 1983-06-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-06-11 1986-12-11 1987-06-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-06-11 1990-12-11 1991-06-12 $7700.00 Window Closed / Lapsed

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