摘要:

AbstractThe physical and chemical characteristics that influence the conversion of fuel nitrogen to nitrogen oxides during coal char combustion were theoretically examined by using a simplified model in which nitric oxide is an intermediate product between fuel nitrogen and N2.It was found that diffusion‐reaction interactions were important in determining the selectivity of the char particle toward nitric oxide production. At low temperature fluidized bed combustion conditions, pore size is important, and low conversion of fuel nitrogen to nitric oxide is favored by long narrow pores. Under high temperature, pulverized coal combustion conditions, the model provided insight into mechanisms of nitric oxide formation and predicted the observed weak temperature dependence of fuel nitrogen conversion, as well as a significant effect of particle siz

ISSN:0001-1541    

DOI:10.1002/aic.690220112

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractSecondary nucleation of magnesium sulfate and citric acid was studied in a seeded back mixed crystallizer. The MSMPR type of exponential population density distribution was obtained above 8 μm size in quasi steady state operation. Growth rates were satisfactorily correlated with supersaturation. Nucleation rates correlated with supersaturation and slurry properties. Agitation level (RPM) did not have any significant effect on the nucleation rates, presumably implying surface regeneration limited nucleation

ISSN:0001-1541    

DOI:10.1002/aic.690220113

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractExperimental solubility data have been obtained for sixteen organic solutes in molten polystyrene by a gas chromatographic procedure for temperatures from 408° to 503°K and pressures to 4 atm. The effects of diffusion and adsorption of the solute on the substrate were considered. The Henry's law constants resulting from this study and those obtained by other investigators were related to the reduced temperature. The effect of pressure on the Henry's law constants is also discussed, and a relationship is presented for the heat of solutio

ISSN:0001-1541    

DOI:10.1002/aic.690220114

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractExperimental residence time distribution functions for the liquid and solids conveying processes by a screw conveyer and for the polymer in a plasticating extruder were obtained by using a radioactive tracer technique. A comparison was made between the experimental results and several theoretical models available for melt extrusion and mixing processes.

ISSN:0001-1541    

DOI:10.1002/aic.690220115

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractFrom thermal response measurements, ice nucleation rates in distilled water, sugar solutions, and fruit juices were determined for a stirred, batch‐seeded crystallizer. High resolution thermometry permitted use of initial sub‐coolings between 0.01° and 0.2°K. Nucleation increased with approximately the second power of subcooling. Applications to freeze concentration are consi

ISSN:0001-1541    

DOI:10.1002/aic.690220116

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractThe suboptimal control policy obtained from series expansion of time‐delay terms is useful when the delays are small. The second method involving direct search on the constant gain matrix is applicable even for large delays. Both of these proposed methods are computationally simple and lead to easy implementation in practic

ISSN:0001-1541    

DOI:10.1002/aic.690220117

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractTransient diffusion ofn‐butane, iso‐butane, and 1‐butene in synthetic CaX(Na) spherical pellets is studied in a constant volume, well‐stirred system. The intracrystalline diffusion coefficients are in the order of 10−14cm2/s, and the activation energy is about 7.0 Kcal/g‐mole. Experimental data agree well with a mathematical model developed to describe transien

ISSN:0001-1541    

DOI:10.1002/aic.690220118

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractA new model for predicting the hydrodynamics, flow distribution, and mass transfer efficiency of multipass distillation trays is presented. Separate submodels apply to two‐, three‐, and four‐pass trays, which may be any type of cross flow tray with downcomers: sieve, valve, or bubble cap.It was found that the liquid/vapor flow ratio in one pass of a poorly designed multipass tray can be several times that in adjacent passes, and that the mean tray efficiency of such a tray is substantially less than the optimum possible. It is shown that multipass trays can be designed with essentially perfect flow distribution and optimum (maximum) overall tray effic

ISSN:0001-1541    

DOI:10.1002/aic.690220119

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractRates of oxidation of dilute, aqueous solutions of acetic acid were measured at 252° to 286°C and 67 atm in liquid full and trickle‐bed reactors packed with ferric oxide catalyst particles. Predicted global rates and conversions indicated that localized vaporization and liquid channeling could affect trickle‐bed perfor

ISSN:0001-1541    

DOI:10.1002/aic.690220120

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY

摘要:

AbstractThe stability of a thermally stratified, saturated porous media through which mass is being ejected is considered theoretically. The stability parameter is a flow modified D'Arcy‐Rayleigh number and is a function of a single scalar variable, the dimensionless through‐flow strength. Results of both linear and energy theory are given, and it is seen that the fluid can lose stability by either a buoyantly driven mode or by a continuous analogue of the Saffman‐Taylor

ISSN:0001-1541    

DOI:10.1002/aic.690220121

出版商:American Institute of Chemical Engineers    

年代:1976

数据来源: WILEY