US5018458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furnace combustion zone temperature control method
Assignee: US Filter Zimpro Inc
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Filing: 1990-09-12
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Granted: 1991-05-28
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Expires: 2010-09-12
Abstract
Abstract An improved method for controlling combustion zone temperature in a furnace independent of flue gas oxygen content is disclosed. The method comprises supplying a carrier gas containing a fine mist of liquid water droplets to the furnace combustion zone to control the maximum temperature within the combustion zone. The invention is applicable to both multiple hearth furnaces and fluidized bed furnaces, protecting the refractory furnace lining from damage.
Inventors
- 👤 Glover C. McIntyre
- 👤 Robert J. Lacombe
- 👤 Russell G. Forbess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:42
CPC Classifications
F; F23; F23G; F23G5/00; F23G5/30; F23G5/38; F23L; F23L7/00; F23L7/002
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
185 words
A method for controlling temperature in a combustion zone in a furnace, independent of flue gas oxygen content, comprising the steps: (a) supplying combustion air to said furnace for combustion of a fuel therein; (b) providing a plurality of low volume gas flow entry ports to said combustion zone in said furnace with carrier gas continuously flowing through said ports into said combustion zone; (c) selecting a set point value for said combustion zone temperature which, upon said temperature exceeding said set point value, commences generation of a fine water mist external said combustion zone by mist generating means within said carrier gas, said mist flowing into said combustion zone with said carrier gas and reducing temperature within said combustion zone by vaporization therein; and (d) adding a proportionately greater amount of water mist to said carrier gas as the temperature of said combustion zone deviates above said set point value, said amount of water mist added limited by the capacity of said mist generating means, and ceasing said water mist generation upon said combustion zone temperature falling to or below said set point value.
Claim 2
Independent Claim
185 words
A method for controlling temperature in a combustion zone in a furnace, independent of flue gas oxygen content, comprising the steps: (a) supplying combustion air to said furnace for combustion of a fuel therein; (b) providing a plurality of low volume gas flow entry ports to said combustion zone in said furnace with carrier gas continuously flowing through said ports into said combustion zone; (c) selecting a set point value for said combustion zone temperature which, upon said temperature exceeding said set point value, commences generation of a fine water mist external said combustion zone by mist generating means within said carrier gas, said mist flowing into said combustion zone with said carrier gas and reducing temperature within said combustion zone by vaporization therein; and (d) adding a proportionately greater amount of water mist to said carrier gas as the temperature of said combustion zone deviates above said set point value, said amount of water mist added limited by the capacity of said mist generating means, and ceasing said water mist generation upon said combustion zone temperature falling to or below said set point value.
Claim 3
Dependent Claim
23 words
A process according to claim 1 wherein less than a stoichiometric amount of combustion air is supplied to said furnace for fuel combustion.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein more than a stoichiometric amount of combustion air is supplied to said furnace for fuel combustion.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein said carrier gas is air.
Claim 6
Dependent Claim
32 words
A process according to claim 1 wherein said water mist and carrier gas flow to said combustion zone at a maximum weight ratio of about 50 parts water to 1 part air.
Claim 7
Dependent Claim
32 words
A process according to claim 1 wherein said water mist and carrier gas flow to said combustion zone at a maximum weight ratio of about 40 parts water to 1 part air.
Claim 8
Dependent Claim
41 words
A process according to claim 1 wherein said water mist and carrier gas flow to said combustion zone at a weight ratio of between about 25 parts water to 1 part air and about 1 part water to 1 part air.
Claim 9
Dependent Claim
17 words
A process according to claim 1 wherein said combustion zone is contained within a multiple hearth furnace.
Claim 10
Dependent Claim
20 words
A process according to claim 8 wherein said combustion air is supplied to the bottom of a multiple hearth furnace.
Claim 11
Dependent Claim
20 words
A process according to claim 8 wherein said combustion air is supplied to individual hearths of a multiple hearth furnace.
Claim 12
Dependent Claim
26 words
A process according to claim 8 wherein at least two low volume gas flow entry ports are provided for each hearth contained within said combustion zone.
Claim 13
Dependent Claim
23 words
A according to claim 8 wherein four low volume gas flow entry ports are provided for each hearth contained within said combustion zone.
Claim 14
Dependent Claim
17 words
A process according to claim 1 wherein said combustion zone is contained in a fluidized bed furnace.
Claim 15
Dependent Claim
23 words
A process according to claim 13 wherein said carrier gas entry ports are located in the freeboard area of a fluidized bed furnace.
Claim 16
Dependent Claim
25 words
A process according to claim 13 wherein four low volume gas flow entry ports are provided in the freeboard area of a fluidized bed furnace.
Claim 17
Dependent Claim
15 words
A process according to claim 1 wherein said mist generating means is a two-fluid atomizer.
Claim 18
Dependent Claim
16 words
A process according to claim 1 wherein said mist generating means is an ultrasonic vaporizing device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |