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00660 Burner-boiler assemblies: Standard v. long-term efficiency
09 96/00659 Application of mlcroacopy to the investigation of brown coal pyrolysis Shibaoka, M. et al., Fuel, Nov. 1995, 74, (11), 1648-1653. To examine the influence of calcium on the mechanisms of brown coal pyrolysis and gasification, the morphology of chars from raw and calciumexchanged Yalloum brown coal was analysed. The chars were obtained by slow pyrolysis in a therm0 gravimetric analyser and rapid pyrolysis in fluidized bed reactors operating at atmospheric pressure and at 1.1 MPa. They were examined by optical microsocpy to determine reflectance and the percentage of particles that had become plastic during pyrolysis. In addition to confirming calcium’s inhibiting effect on tar yield, the results from the rapid pyrolysis experiments show that in the presence of calcium, char reflectivity decreases, char H/C ratio increases, and the proportion of particles going through a plastic stage decreases. Calcium’s inhibition of plasticity development is augmented by high pressure in the fluidized bed reactor. Burner-holler assemblies: Standard v. long-term 96lOO660 efficiency Martin, M. GAZ d’aujourd’hui, Oct. 1995, 119, (lo), 437-440. (In French) The performance of the burner-boiler assembly has been considerably enhanced over the years by the combined efforts of burner and boiler manufacturers, who often work in unison. Nowadays, proposed European standards governing equipment and installation are proving difficult to be put into practice. In a conventional boiler house providing space heating, burner combustion is subject to numerous large-scale variations which can only be taken into account by the use of very sophisticated,, and therefore very expensive, technologies. Even then, these technologies have to be compatible with reasonable or specific pay-back periods. 96/00661 Burners of Industrial boilers field-tested Gas, Oct. 1995, 115, (IO), 28-29, 31. (In Verheij V. and Aptroot, R. Flemish) In the ‘93-‘94 heating season, Gasunie examined the performance of 42 gas-fired burners of industrial boilers. The field tests showed that mean NO_ emission of the installations concerned was 75 me/m’. Under full-load conhitions, only 26% of the installations met Ihe NO, emission requirement of 60 mg/m’. The current statutory NO, emission requirement of 100 mg/m’ was met by more than 85% of the burners. Most burners produced hardly any CO. Some installations, however, produced very much more carbon monoxide. Over 90% of the users was positive about the performance of the burners. Flame failures occurred only occasionally. Failure particularly related to components of the gas/air circuit.
Catalyzed NO., formation under fluldized-bed combustion conditions
96100662
Makarytchev, S. V. et al., Chem. Eng. Sci., 1995, 50, (15), 2489-2490. The same approach of S. Makarytchev (1995) was used to analyze limestone-catalyzed NO, formation by comparing experimental NO, emissions from a bench-scale stationary fluidized-bed combustor with multicomponent (50 gas-phase, 7 solid-phase species) equilibrium calculations at 0.6-1.4:l air ratio. 96100663
CFB operates at 2400 pslg, with reheat, firing waste
coal Ansell, Colver nomic strated,
J. et al., Power, 1995, 139, (4), 57-58. represents a unique response to regional environmental and ecochallenges. Community development concepts are being demonalong with new circulating fluidized-bed design parameters.
Change of physicochemlcal propertles of thermal coals and thermal brlquets In relation to conditions for thermal treatment of Berezovsk coal during rapid heatlng 96/00664
Kird, V. S. et al., Khim. Tverd. Topl. (Moscow), 1995, (3), 73-76. (In Russian) Reports on a study of the pyrolysis degree and structure of the resultant solid product during rapid heating of brown coal. The differences in properties and supermolecular structure of thermal coals and briquets are also discussed.
Characterizing fuels for atmospheric fluidized bed 96100665 combustion Marban, G. et aZ., Combustion & Flame, Oct. 1995, 103, (l), 41-58. A complete methodology for characterizing coal combustion in atmospheric fluidized bed reactors is presented. The methodology comprises studies of fragmentation and particle size variations during combustion, necessary to allow an accurate determination of kinetic parameters and attrition rates.
96100666
Coal gaslfler with char recycle
Kobayashi, S. (Assigned to) Ishikawajima Harima Heavy Ind., JAP. Pat. JP.O7,90,285, Apr. 1995. The gasifier consists of a long cylindric high-velocity fluidized-bed section for contacting coal with gasifying agent, and a means for separating solids from the gases and recycling the separated solids back to the lower portion of the bed.
96100667
Combustion (burners, combustion systems)
Coal gasifler with prevention of slag flylng
Tanaka, S. and Koyama, JP.O7,53,969, Feb. 1995.
(Assigned to) Hitachi Ltd., JAP. Pat.
S.
The coal gasifier consists of a cylindric gasification chamber with side burners lo create a cyclone flow in the central section, and arranged with fins above the bottom of the chamber and below the burners to prevent slag from flying out.
Coal/water slurry: Path to economical use of coal Melick, T. and Battista,J.
Power, 1995, 139, (3), 77-78.
The paper discusses the resolving technique, operational, and economic issues in co-firing coal fines in slurry form in a new low-NO, burner at an old station.
96100669 Combustion behavior and surface characterlstlcs of pulverized coal particle Kobayashi,N. et al., Muki Mater&u, 1995, 2, (255), 115-121. Pulverized coal samples with two kinds of particle size were fed into a vertical laminar flow furnace and burned in 0, at 1073-1223 K. Linear relationships between unburned carbon ratio aid residence time in the furnace were observed for large particles, and the combustion process could be divided into two regions of rapid and slow rates.
96/00670 Combustion characterlstlcs of a clrculatlng fluldized bed gas combustor for low-calorific fuel Kataoka, A. et al., (In Japanese)
Kagah
Kogaku Ronbunshu, 1995, 21, (4), 793-799.
A circulating fluidized bed equipped with a nozzle burner part of the riser for low-calorific gas combustion is described. the effect of sensible heat of solid particles on combustion and NO, emissions and control were studied by using model tion gas.
96100671
in the bottom In this study, characteristics coal gasifica-
Combustion reactivity of chars
Uysal, B. Z. NATO ASI Ser., Ser. C, Composition, Geochemistry & Conversion of Oil Shales, 1995, (455), 365-378. The a er discusses the combustion kinetics of chars with special reference to 01.Pfs ale m fluidized-beds. The total time required for carbon burn off is considered for both kinetic controlled combustion and mass transfer controlled combustion.
96100672 A comparative study on NO, emlsslons from coal burning fluidized-bed combustors Bayat, B. et al., IChemE Rex Event, 1st Eur. Con$ Young Rex Chem. Eng., Inst. Chem. Eng., Rugby, UK, 1995, 1, 432-434. The paper presents a study of the factors influencing NO, and N,O emissions from coal combustion in a circulating fluidized bed and a bubbling fluidized b-d.
96100673 Comparison of the combustion behsvlour of pulverlzed waste tyres and coal Atal, A. and Levendis,
Y. A.
Fuel, Nov. 1995, 74, (ll),
1570-1581.
Comparative combustion studies were performed on particles obtained from pulverized bituminous coal and waste automobile tyres (rubber). Particle size cuts of 75-90 and 180-272 urn were burned in a thermogravimetric analyser, at low heating rates, and in an electrically heated drop-tube furnace, at high heating rates. The combustion of individual particles in the drop-tube furnace was observed with three-colour pyrometry, to obtain time-temperature histories and with high-speed cinematography to record flame-particle size histories. Combustion was conducted at a gas temperature of 1450K, in air.
96100674
The coupling of conical wrinkled lamlnar flames
with gravity Kostiuk, L. W. and Cheng, R. K. (l), 27-40.
Combustion & Flame, Oct. 1995, 103,
The work explores the influences that gravity has on conical premixed laminar and mildly turbulent flames (i.e., wrinkled laminar flames). The approach is to compare overall flame characteristics in normal (+g), reverse (-g), and micro-gravity (ug). Laser schlieren is the principal diap;nostic for-ug experimen?s. Laboratory investigations of +g’and -g flames also include two components laser doppler anemometry. The results obtained in a wide range of flow, mixture and turbulence conditions show that gravity has a profound effect on the lean stabilization limits, features of the flowfield, and mean flame heights.
Fuel and Energy Abstracts January 1996 41
Catalyzed NO., formation under fluldized-bed combustion conditions
96100662
Makarytchev, S. V. et al., Chem. Eng. Sci., 1995, 50, (15), 2489-2490. The same approach of S. Makarytchev (1995) was used to analyze limestone-catalyzed NO, formation by comparing experimental NO, emissions from a bench-scale stationary fluidized-bed combustor with multicomponent (50 gas-phase, 7 solid-phase species) equilibrium calculations at 0.6-1.4:l air ratio. 96100663
CFB operates at 2400 pslg, with reheat, firing waste
coal Ansell, Colver nomic strated,
J. et al., Power, 1995, 139, (4), 57-58. represents a unique response to regional environmental and ecochallenges. Community development concepts are being demonalong with new circulating fluidized-bed design parameters.
Change of physicochemlcal propertles of thermal coals and thermal brlquets In relation to conditions for thermal treatment of Berezovsk coal during rapid heatlng 96/00664
Kird, V. S. et al., Khim. Tverd. Topl. (Moscow), 1995, (3), 73-76. (In Russian) Reports on a study of the pyrolysis degree and structure of the resultant solid product during rapid heating of brown coal. The differences in properties and supermolecular structure of thermal coals and briquets are also discussed.
Characterizing fuels for atmospheric fluidized bed 96100665 combustion Marban, G. et aZ., Combustion & Flame, Oct. 1995, 103, (l), 41-58. A complete methodology for characterizing coal combustion in atmospheric fluidized bed reactors is presented. The methodology comprises studies of fragmentation and particle size variations during combustion, necessary to allow an accurate determination of kinetic parameters and attrition rates.
96100666
Coal gaslfler with char recycle
Kobayashi, S. (Assigned to) Ishikawajima Harima Heavy Ind., JAP. Pat. JP.O7,90,285, Apr. 1995. The gasifier consists of a long cylindric high-velocity fluidized-bed section for contacting coal with gasifying agent, and a means for separating solids from the gases and recycling the separated solids back to the lower portion of the bed.
96100667
Combustion (burners, combustion systems)
Coal gasifler with prevention of slag flylng
Tanaka, S. and Koyama, JP.O7,53,969, Feb. 1995.
(Assigned to) Hitachi Ltd., JAP. Pat.
S.
The coal gasifier consists of a cylindric gasification chamber with side burners lo create a cyclone flow in the central section, and arranged with fins above the bottom of the chamber and below the burners to prevent slag from flying out.
Coal/water slurry: Path to economical use of coal Melick, T. and Battista,J.
Power, 1995, 139, (3), 77-78.
The paper discusses the resolving technique, operational, and economic issues in co-firing coal fines in slurry form in a new low-NO, burner at an old station.
96100669 Combustion behavior and surface characterlstlcs of pulverized coal particle Kobayashi,N. et al., Muki Mater&u, 1995, 2, (255), 115-121. Pulverized coal samples with two kinds of particle size were fed into a vertical laminar flow furnace and burned in 0, at 1073-1223 K. Linear relationships between unburned carbon ratio aid residence time in the furnace were observed for large particles, and the combustion process could be divided into two regions of rapid and slow rates.
96/00670 Combustion characterlstlcs of a clrculatlng fluldized bed gas combustor for low-calorific fuel Kataoka, A. et al., (In Japanese)
Kagah
Kogaku Ronbunshu, 1995, 21, (4), 793-799.
A circulating fluidized bed equipped with a nozzle burner part of the riser for low-calorific gas combustion is described. the effect of sensible heat of solid particles on combustion and NO, emissions and control were studied by using model tion gas.
96100671
in the bottom In this study, characteristics coal gasifica-
Combustion reactivity of chars
Uysal, B. Z. NATO ASI Ser., Ser. C, Composition, Geochemistry & Conversion of Oil Shales, 1995, (455), 365-378. The a er discusses the combustion kinetics of chars with special reference to 01.Pfs ale m fluidized-beds. The total time required for carbon burn off is considered for both kinetic controlled combustion and mass transfer controlled combustion.
96100672 A comparative study on NO, emlsslons from coal burning fluidized-bed combustors Bayat, B. et al., IChemE Rex Event, 1st Eur. Con$ Young Rex Chem. Eng., Inst. Chem. Eng., Rugby, UK, 1995, 1, 432-434. The paper presents a study of the factors influencing NO, and N,O emissions from coal combustion in a circulating fluidized bed and a bubbling fluidized b-d.
96100673 Comparison of the combustion behsvlour of pulverlzed waste tyres and coal Atal, A. and Levendis,
Y. A.
Fuel, Nov. 1995, 74, (ll),
1570-1581.
Comparative combustion studies were performed on particles obtained from pulverized bituminous coal and waste automobile tyres (rubber). Particle size cuts of 75-90 and 180-272 urn were burned in a thermogravimetric analyser, at low heating rates, and in an electrically heated drop-tube furnace, at high heating rates. The combustion of individual particles in the drop-tube furnace was observed with three-colour pyrometry, to obtain time-temperature histories and with high-speed cinematography to record flame-particle size histories. Combustion was conducted at a gas temperature of 1450K, in air.
96100674
The coupling of conical wrinkled lamlnar flames
with gravity Kostiuk, L. W. and Cheng, R. K. (l), 27-40.
Combustion & Flame, Oct. 1995, 103,
The work explores the influences that gravity has on conical premixed laminar and mildly turbulent flames (i.e., wrinkled laminar flames). The approach is to compare overall flame characteristics in normal (+g), reverse (-g), and micro-gravity (ug). Laser schlieren is the principal diap;nostic for-ug experimen?s. Laboratory investigations of +g’and -g flames also include two components laser doppler anemometry. The results obtained in a wide range of flow, mixture and turbulence conditions show that gravity has a profound effect on the lean stabilization limits, features of the flowfield, and mean flame heights.
Fuel and Energy Abstracts January 1996 41