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Tests of the HNPF Plugging Meter

Description: A plugging meter designed for the Hallam Nuclear Power Facility was tested. Plugging performance was satisfactory and excellent reprcducibility was achieved. Although the time limitations precluded complete testing of the automatic control equipment, the tests performed gave satisfactory indication of correct performance. (auth)
Date: February 13, 1961
Creator: Davis, K. A.
Partner: UNT Libraries Government Documents Department

Environmental monitoring summary for the Paducah Plant for 1965 & 1966

Description: Paducah Area (KY). Radiation monitoring of air, vegetation, and water in vicinity of Paducah Plant 1965 to 1966; ATMOSPHERE. Radiation monitoring of, in vicinity of Paducah Plant during 1965 to 1966. WATER. Radiation monitoring of, in vicinity of Paducah Plant during 1965 to 1966; PLANTS. Radiation monitoring of, in vicinity of Paducah Plant during 1965 to 1966; RADIOACTIVITY. Monitoring in air, vegetation, and water in vicinity of Paducah Plant during 1965 to 1966.
Date: January 1, 1967
Creator: Baker, R. C. & Davis, K. A.
Partner: UNT Libraries Government Documents Department

Comparison of biomass and coal char reactivities

Description: Char combustion is typically the rate limiting step during the combustion of solid fuels. The magnitude and variation of char reactivity during combustion are, therefore, of primary concern when comparing solid fuels such as coal and biomass. In an effort to evaluate biomass` potential as a sustainable and renewable energy source, the reactivities of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to determine biomass and coal reactivities and presents results from CPT experiments. The reactivity of six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, were investigated using the CPT apparatus. Results indicate that both of the high-rank coal chars have relatively low reactivities when compared with the higher reactivities measured for the low-rank coal and the biomass chars. In addition, extinction behavior of the chars support related investigations that suggest carbonaceous structural ordering is an important consideration in understanding particle reactivity as a function of extent of burnout. High-rank coal chars were found to have highly ordered carbon structures, where as, both low-rank coal and biomass chars were found to have highly disordered carbon structures.
Date: August 1, 1995
Creator: Huey, S.P.; Davis, K.A. & Hurt, R.H.
Partner: UNT Libraries Government Documents Department

Environmental monitoring summary for the Paducah Plant for 1967 and 1968

Description: Paducah area (KY). Radiation monitoring in, during 1967 and 1968. SURFACE WATERS. Radiation monitoring of, in vicinity of Paducah plant during 1967 and 1968. ENVIRONMENT. Radiation monitoring of, in vicinity of Paducah plant during 1967 and 1968. PLANTS. Radiation monitoring of, in vicinity of Paducah Plant during 1967 and 1968. ATMOSPHERE. Radiation monitoring of, in vicinity of Paducah Plant during 1967 and 1968.
Date: January 1, 1969
Creator: Davis, K.A. & Brown, E.G.
Partner: UNT Libraries Government Documents Department

Near-extinction and final burnout in coal combustion

Description: The late stages of char combustion have a special technological significance, as carbon conversions of 99% or greater are typically required for the economic operation of pulverized coal fired boilers. In the present article, two independent optical techniques are used to investigate near-extinction and final burnout phenomenas. Captive particle image sequences, combined with in situ optical measurements on entrained particles, provide dramatic illustration of the asymptotic nature of the char burnout process. Single particle combustion to complete burnout is seen to comprise two distinct stages: (1) a rapid high-temperature combustion stage, consuming about 70% of the char carbon and ending with near-extinction of the heterogeneous reactions due to a loss of global particle reactivity, and (2) a final burnout stage occurring slowly at lower temperatures. For particles containing mineral matter, the second stage can be further subdivided into: (2a) late char combustion, which begins after the near-extinction event, and converts carbon-rich particles to mixed particle types at a lower temperature and a slower rate; and (2b) decarburization of ash -- the removal of residual carbon inclusions from inorganic (ash) frameworks in the very late stages of combustion. This latter process can be extremely slow, requiring over an order of magnitude more time than the primary rapid combustion stage. For particles with very little ash, the loss of global reactivity leading to early near-extinction is clearly related to changes in the carbonaceous char matrix, which evolves over the course of combustion. Current global kinetic models used for the prediction of char combustion rates and carbon burnout in boilers do not predict the asymptotic nature of char combustion. More realistic models accounting for the evolution of char structure are needed to make accurate predictions in the range of industrial interest.
Date: February 1, 1994
Creator: Hurt, R. H. & Davis, K. A.
Partner: UNT Libraries Government Documents Department

Environmental assessment for the satellite power system concept development and evaluation program-electromagnetic systems compatibility

Description: The EMC analysis addressed only the direct effects of electromagnetic emissions from the SPS on other technological systems. Emissions were defined quite broadly, including not only those from the microwave system, but also thermal blackbody emission and scattered sunlight from the satellite. The analysis is based on the design for an SPS as described in the Reference System Report and some quantitative conclusions, e.g., ranges from rectenna sites at which effects are expected are specific to that design. The methodology and qualitative conclusions, however, apply to an SPS concept using microwave power transmission. Quantitative conclusions have been obtained parametrically and can be adjusted as SPS designs change. The electromagnetic environment that the Reference System would produce, and in which other systems would have to function, is described. As an early part of the EMC Assessment, the problems expected for a hypothetical rectenna site, in the Mojave Desert of southern California, were analyzed in detail. This effort provided an initial quantitative indication of the scope of potential EMC problems and indicated the importance of EMC considerations in rectenna site selection. The results of this analysis are presented. The effects of SPS microwave emissions on important categories of electronic systems and equipment are summarized, with many examples of test results and demonstrated techniques for mitigation of problems encountered. SPS effects on other satellite systems are presented. Astronomical research frequently involves measurement of extremely low levels of electromagnetic radiation and is thus very susceptible to interference. The concerns of both radio astronomy with microwave emissions from SPS and optical astronomy with sunlight scattered from SPS spacecraft are discussed. Summaries of mitigation techniques, cost estimates, and conclusions are presented. (WHK)
Date: January 1, 1981
Creator: Davis, K A; Grant, W B; Morrison, E L & Juroshek, J R
Partner: UNT Libraries Government Documents Department

Coal Combustion Science. Quarterly progress report, October--December 1994

Description: The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: Task 1--Kinetics and mechanisms of pulverized coal char combustion; and Task 2--deposit growth and property development in coal-fired furnaces. The objective of task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. Work is being done in four areas: (a) kinetics of heterogeneous fuel particle populations; (b) char combustion kinetics at high carbon conversion; (c) the role of particle structure and the char formation process in combustion and; (d) unification of the Sandia char combustion data base. The objectives of Task 2 are to provide a self-consistent database of simultaneously measured, time-resolved, ash deposit properties in well-controlled and well-defined environments and to provide analytical expressions that relate deposit composition and structure to deposit properties of immediate relevance to PETC`s Combustion 2000 program. The task include the development and use of diagnostics to monitor, in situ and in real time, deposit properties, including information on both the structure and composition of the deposits.
Date: February 1, 1996
Creator: Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H. & Yang, N.Y.C.
Partner: UNT Libraries Government Documents Department

Coal combustion science. Quarterly progress report, July--September 1994

Description: This document is a quarterly status report of the Coal Combustion Science Project that is being conducted at the Combustion Research Facility, Sandia National Laboratories, Livermore, California. The information reported is for the period July-September 1994. The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project.
Date: September 1, 1995
Creator: Hardesty, D.R.; Baxter, L.L.; Davis, K.A.; Hurt, R.H. & Yang, N.Y.C.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Coal continues to be one of the principal energy sources for electric power generation in the United States. One of the biggest environmental challenges involved with coal utilization is the reduction of nitrogen oxides (NO{sub x}) formed during coal combustion. The most economical method of NO{sub x} abatement in coal combustion is through burner modification. Air-staging techniques have been widely used in the development of low-NO{sub x} pulverized coal burners, promoting the conversion of NO{sub x} to N{sub 2} by delaying the mixing in the fuel-rich zone near the burner inlet. Previous studies have looked at the mechanisms of NO{sub x} evolution at relatively low temperatures where primary pyrolysis is dominant, but data published for secondary pyrolysis in the pulverized coal furnace are scarce. In this project, the nitrogen evolution behavior during secondary coal pyrolysis will be explored. The end result will be a complete model of nitrogen evolution and NO{sub x} precursor formation due to primary and secondary pyrolysis.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Reduction of NO{sub x} emission is an important environmental issue in pulverized coal combustion. The most cost-effective approach to NO{sub x} reduction is air-staging which can also operate with additional down-stream techniques such as reburning [1]. Air staging promotes the conversion of NO{sub x} precursors (HCN, NH{sub 3}, etc.) to N{sub 2} by delaying the oxygen supply to the greatest extent when those nitrogen species are released during devolatilization. Such a delay gives the primary volatiles a chance to undergo secondary reactions, including tar cracking and soot formation. Secondary reactions of volatiles largely determine the fate of the ultimate NO{sub x} production from pyrolysis, therefore a detailed investigation into the transformation of nitrogen species during secondary reactions and effects of soot on nitrogen release is critical for design and implementation of new pollution control strategies. Current nitrogen models (including the CPD model at BYU) only simulate the nitrogen release during primary pyrolysis, which happens at low temperatures. This project helps to build a nitrogen release model that accounts for secondary reactions and the effects of soot at temperatures relevant to industrial burners.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Reduction of NO{sub x} emission is an important environmental issue in pulverized coal combustion. Final emissions of NO{sub x} are strongly affected by the nitrogen release during devolatilization, which is the first stage of coal combustion. The most cost-effective approach to NO{sub x} reduction is air-staging which can also operate with additional down-stream techniques such as reburning [1]. Air staging promotes the conversion of NO{sub x} precursors (HCN, NH{sub 3}, etc.) to N{sub 2} by delaying the oxygen supply to the greatest extent when those nitrogen species are released during devolatilization. Such a delay gives the primary volatiles a chance to undergo secondary reactions, including tar cracking and soot formation. Secondary reactions of volatiles largely determine the fate of the ultimate NO{sub x} production from pyrolysis, therefore a detailed investigation into the transformation of nitrogen species during secondary reactions and effects of soot on nitrogen release is critical for design and implementation of new pollution control strategies. Current nitrogen models (including the CPD model at BYU) only simulate the nitrogen release during primary pyrolysis, which happens at low temperatures. This project helps to build a nitrogen release model that accounts for secondary reactions and the effects of soot at temperatures relevant to industrial burners.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Coal continues to be one of the principal energy sources for electric power generation in the United States. One of the biggest environmental challenges involved with coal utilization is the reduction of nitrogen oxides (NO{sub x}) formed during coal combustion. The most economical method of NO{sub x} abatement in coal combustion is through burner modification. Air-staging techniques have been widely used in the development of low-NO{sub x} pulverized coal burners, promoting the conversion of NO{sub x} to N{sub 2} by delaying the mixing in the fuel-rich zone near the burner inlet. Previous studies have looked at the mechanisms of NO{sub x} evolution at relatively low temperatures where primary pyrolysis is dominant, but data published for secondary pyrolysis in the pulverized coal furnace are scarce. In this project, the nitrogen evolution behavior during secondary coal pyrolysis will be explored. The end result will be a complete model of nitrogen evolution and NO{sub x} precursor formation due to primary and secondary pyrolysis.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Reduction of NO{sub x} emission is an important environmental issue in pulverized coal combustion. The most cost-effective approach to NO{sub x} reduction is air-staging which can also operate with additional down-stream techniques such as reburning [1]. Air staging promotes the conversion of NO{sub x} precursors (HCN, NH{sub 3}, etc.) to N{sub 2} by delaying the oxygen supply to the greatest extent when those nitrogen species are released during devolatilization. Such a delay gives the primary volatiles a chance to undergo secondary reactions, including tar cracking and soot formation. Secondary reactions of volatiles largely determine the fate of the ultimate NO{sub x} production from pyrolysis, therefore a detailed investigation into the transformation of nitrogen species during secondary reactions and effects of soot on nitrogen release is critical for design and implementation of new pollution control strategies. Current nitrogen models (including the CPD model at BYU) only simulate the nitrogen release during primary pyrolysis, which happens at low temperatures. This project helps to build a nitrogen release model that accounts for secondary reactions and the effects of soot at temperatures relevant to industrial burners.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: During the last reporting period the experimental setup in the University of Utah Laminar-Flow Drop Tube was modified to allow for batch experiments. This modification was made in order to guarantee complete conversion of the char in the reactor. Once the setup was optimized, the effect of particle size, oxygen concentration, type of char and NO bulk concentration on the conversion of char-N to NO was evaluated. In this report, we present the results obtained for different chars and for different NO background concentrations. The effect of oxygen and particle size is currently being analyzed and will be presented in the final report. Experiments were performed with three different carbonaceous materials and were conducted at temperatures close to that of pulverized combustion conditions (1700 K) in a laminar drop tube reactor under inert and oxidizing atmospheres. The results obtained show that the process of NO reduction on the char surface plays an important role on the total amount of char-N converted to NOx. This effect tends to reduce as the NO background concentration is reduced and doesn't seem to strongly depend on the nature of the char. Some of these results were presented at the 2nd Joint Meeting of the US Sections of the Combustion Institute, held in March of 2001. In addition to the experimental observations on char-N conversion to NO, a single particle model was developed and the predictions of the model were compared with the experimental results. Although the model predicts the linear reduction on the conversion of char-N to NO, it overpredicts the general value. A higher value for the rate of NO destruction on char surface doesn't seem to explain this phenomenon, which may be more related to the availability of char surface for the destruction of NO.
Date: June 1, 2001
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Fletcher, T.H. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: Coal continues to be one of the principal energy sources for electric power generation in the United States. One of the biggest environmental challenges involved with coal utilization is the reduction of nitrogen oxides (NO{sub x}) formed during coal combustion. The most economical method of NO{sub x} abatement in coal combustion is through burner modification. Air-staging techniques have been widely used in the development of low-NO{sub x} pulverized coal burners, promoting the conversion of NO{sub x} to N{sub 2} by delaying the mixing in the fuel-rich zone near the burner inlet. Previous studies have looked at the mechanisms of NO{sub x} evolution at relatively low temperatures where primary pyrolysis is dominant, but data published for secondary pyrolysis in the pulverized coal furnace are scarce. In this project, the nitrogen evolution behavior during secondary coal pyrolysis will be explored. The end result will be a complete model of nitrogen evolution and NO{sub x} precursor formation due to primary and secondary pyrolysis.
Date: April 1, 2000
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: An initial testing campaign was carried out during the summer of 2000 to evaluate the impact of multiburner firing on NOx emissions. Extensive data had been collected during the Fall of 1999 and Spring of 2000 using a single pulverized-coal (PC) burner, and this data collection was funded by a separate Department of Energy program, the Combustion 2000 Low Emission Boiler System (LEBS) project under the direction of DB Riley. This single-burner data was thus available for comparison with NOx emissions obtained while firing three burners at the same overall load and operating conditions. A range of operating conditions were explored that were compatible with single-burner data, and thus the emission trends as a function of air staging, burner swirl and other parameters will be described below. In addition, a number of burner-to-burner operational variations were explored that provided interesing insight on their potential impact on NOx emissions. Some of these variations include: running one burner very fuel rich while running the others fuel lean; varying the swirl of a single burner while holding others constant; increasing the firing rate of a single burner while decreasing the others. In general, the results to date indicated that multiburner firing yielded higher NOx emissions than single burner firing at the same fuel rate and excess air. At very fuel rich burner stoichiometries (SR < 0.75), the difference between multiple and single burners became indistinguishable. This result is consistent with previous single-burner data that showed that at very rich stoichiometries the NOx emissions became independent of burner settings such as air distributions, velocities and burner swirl.
Date: June 1, 2001
Creator: E.G.Eddings; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Davis, K.A.; Heap, M.P. et al.
Partner: UNT Libraries Government Documents Department

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

Description: The focus of this program is to provide insight into the formation and minimization of NO{sub x} in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO{sub x} emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames--particularly under low NO{sub x} conditions. A CO/H{sub 2}/O{sub 2}/N{sub 2} flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state {sup 13}C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; ...
Date: January 1, 2002
Creator: Eddings, E.G.; Molina, A.; Pershing, D.W.; Sarofim, A.F.; Fletcher, T.H.; Zhang, H. et al.
Partner: UNT Libraries Government Documents Department

OPTIMIZED FUEL INJECTOR DESIGN FOR MAXIMUM IN-FURNACE NOx REDUCTION AND MINIMUM UNBURNED CARBON

Description: Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers, �in-furnace NO x control,� which includes: staged low-NO x burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of �in-furnace� NO x control processes. 2) To devise new, or improve existing, approaches for maximum �in-furnace� NO x control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) laboratory experiments and computer modeling to improve our two-phase mixing predictive capability; 3) evaluation of commercial low-NO x burner fuel injectors to develop improved designs, and 4) demonstration of coal injectors for reburning and low-NO x burners at commercial scale. The specific objectives of the two-phase program are to: 1 Conduct research to better understand the interaction of heterogeneous chemistry and two phase mixing on NO reduction processes in pulverized coal combustion. 2 Improve our ability to predict combusting coal jets by verifying two phase mixing models under conditions that simulate the near field of low-NO x burners. 3 Determine the limits on NO control by in-furnace NO x control technologies as a function of furnace design and coal type. 5 Develop and demonstrate improved coal injector designs for commercial low-NO x burners and coal reburning systems. 6 Modify the char burnout model in REI�s coal combustion code to take account of recently obtained fundamental data on char ...
Date: January 1, 1998
Creator: SAROFIM, A.F.; LISAUSKAS, BROWN UNIVERSITY. R.A.; D.B. RILEY, INC.; EDDINGS, E.G.; BROUWER, J.; KLEWICKI, J.P. et al.
Partner: UNT Libraries Government Documents Department