US4466363A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of igniting a pulverized coal annular burner flame
Assignee: Hitachi Zosen Inova Steinmueller GmbH
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Filing: 1982-03-17
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Granted: 1984-08-21
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Expires: 2002-03-17
Abstract
Abstract A method of ignition of a coal dust annular burner flame having an internal back flow region. The ignition energy is introduced centrally into the internal back flow region of the coal dust annular burner flame, and is delivered entirely or at least partially by a dust-ignition flame. The dust air-dust weight ratio for the dust-ignition flame is smaller than that of the main burner flame, being either 0.5 to 1.0, or 0.2 to 0.5, compared with a ratio of 1.5 to 2.0 for the main burner flame.
Inventors
- 👤 Klaus Leikert
- 👤 Sigfrid Michelfelder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:33
CPC Classifications
F; F23; F23D; F23D1/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
241 words
A method of igniting a coal dust fired main burner wherein the main burner has an internal back flow region and is ignited by a dust-ignition flame introduced through a central core passage, the main burner having air introduced through a main air passage and pulverized solid fuel introduced through a dust conduit wherein the main air passage has an annular section surrounding an annular section of the dust conduit, which annular section of the dust conduit surrounds the central core passage through which the ignition flame is introduced, the method comprising the steps of: introducing the dust ignition flame centrally into the internal back flow region by injecting it centrally through the central core passage; utilizing coal dust entrained in air as an ignition fuel with the ratio of dust-laden air to dust for the ignition flame being in the range of 0.2 to 1.0 while the ratio for the burner flame is in the range of 1.5 to 2.0; burning the ignition flame at a smaller air number than the main burner flame with the air number for the ignition flame being in the range of 0.8 to 1.1 while that of the main flame being in the range of 1.1 to 1.3; supplying combustion air to the ignition flame by connecting the central core passage to the main air passage, and providing a greater tangential combustion-air velocity component for said dust-ignition flame than for the main burner flame.
Claim 2
Independent Claim
241 words
A method of igniting a coal dust fired main burner wherein the main burner has an internal back flow region and is ignited by a dust-ignition flame introduced through a central core passage, the main burner having air introduced through a main air passage and pulverized solid fuel introduced through a dust conduit wherein the main air passage has an annular section surrounding an annular section of the dust conduit, which annular section of the dust conduit surrounds the central core passage through which the ignition flame is introduced, the method comprising the steps of: introducing the dust ignition flame centrally into the internal back flow region by injecting it centrally through the central core passage; utilizing coal dust entrained in air as an ignition fuel with the ratio of dust-laden air to dust for the ignition flame being in the range of 0.2 to 1.0 while the ratio for the burner flame is in the range of 1.5 to 2.0; burning the ignition flame at a smaller air number than the main burner flame with the air number for the ignition flame being in the range of 0.8 to 1.1 while that of the main flame being in the range of 1.1 to 1.3; supplying combustion air to the ignition flame by connecting the central core passage to the main air passage, and providing a greater tangential combustion-air velocity component for said dust-ignition flame than for the main burner flame.
Claim 3
Dependent Claim
30 words
A method in combination according to claim 1, which includes the step of providing a smaller axial combusion-air velocity component for said dust-ignition flame than for the main burner flame.
Claim 4
Dependent Claim
24 words
A method in combination according to claim 1, which includes the step of providing an ignition burner having an igniter which is operated electrically.
Claim 5
Dependent Claim
28 words
A method in combination according to claim 1, which includes the step of operating said ignition flame with the same source of fuel used with the main burner.
Claim 6
Dependent Claim
23 words
A method in combination according to claim 1, wherein said ratio for said dust-ignition flame is in a range of 0.5 to 1.0.
Claim 7
Dependent Claim
34 words
A method in combination according to claim 1, including steps of: operating with the dust-laden air to dust-weight ratio for the dust ignition flame in a ratio having a range of 0.2 to 0.5.
Claim 8
Dependent Claim
43 words
A method in combination according to claim 6, including the steps of: simultaneously providing an air factor of λ=0.4 to 0.8 for dust ignition flame operation; and taking the additional air flow necessary for complete combustion from overflow-leakage air of the main burner.
References Cited (Backward Citations)
US4221174A
Cited
US4241673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |