09 Combustion (burners, combustion systems)

global reaction rate mechanism. Good agreement is found between the model expressions and pressure fluctuation co-variances evaluated from DNS.

00/06466 Manufacture method of caking aids for coal charge addition Araki, T. ef al. Jpn. Kokai Tokkyo Koho JP 11 246,866 [99 246,866] (Cl. ClOC1/04), 14 Sep 1999, Appl. 1998/49,446, 2 Mar 1998. 4. (In Japanese) A description of a method for manufacturing caking aids is presented. The process comprises of flash distilling coal tar raw material in a two stage flash distillation tower, which has-a lower chamber and an upper chamber separated by a chimney tray. Under vacuum conditions, the coal tar is withdrawn from the bottom of the upper chamber for reheating, the heated coal tar is then blown from the bottom of the lower chamber, so the coal-tar’s low boiling components can be evaporated and separated.

WI00469 Methane combustion in the combined heating power plant of Lohberg colliery, Germany Schwenger, J. and Heydemann, H. Glueckauf, 1999, 135, (IO), 653-658. (In German) Presented are the exueriences of a combined heatinrr-Dower olant, involved in the combustion of mine gas from the Lohbeig co&y in Germany. The mine gas contained 38.1% CH4 beneath 49.6% Nz and 10.4% O2 and had a heating value of 4.215 kWh/m3. The raw gas came from a depth of about lob0 m with a temperature of 40-lo”, was saturated with moisture and contained particles of aerosol. The station was also equipped to burn natural gas as an alternative or supplemental fuel, so that the operation could continue uninterrupted when the mine gas supply failed. Hot water up to 115” and electricity were produced by the plant.

00100470 Method for management of coal charge in coke oven Nishimura, M. et al. Jpn. Kokai Tokkyo Koho JP 11 256,169 [99 256,169] (Cl. ClOB57/08), 21 Sep 1999, Appl. 1998/65,243, 16 Mar 1998. 6. (In Japanese) The management of coal charge in a coke oven involves the pulverized raw material coal that is to be charged into the coke oven beine adjusted. The basis of the adjustment is on a pre-determined relationship among particle-size distribution, bulk density and dusting amount.

W/W471 Modelllng and measurements of the pyrolysis of large wood particles Larfeldt, J. et al. Fuel, 2000, 79, (13), 1637-1643. The influence from structural changes, heat transfer properties of dry wood and pyrolysis mechanism on the pyrolysis of large wood particles were studied. Measurements of temperature distribution and mass loss were performed on cylindrical samples of dry birch wood during pyrolysis in an inert atmosphere at 700°C. A model of wood pyrolysis was modified to include structural changes. Comparisons of measure- ments and model simulations show that the inclusion of a shrinking model reduces the time of pyrolysis substantially. The varying interior heating rate was found to influence the choice of pyrolysis mechanism. Of four pyrolysis mechanisms found in literature, only one was found to be in agreement with the measurements.

00100472 Modelllng and simulation of time-dependent coal combustion processes in stacks Chejne, F. Fuel, 2000, 79, (8), 987-997. A time-dependent mathematical model and a numerical algorithm have been developed to simulate the combustion of piled coal particles. The model can predict the evolution profiles of unburned solid fraction along the bed height, the gas composition, heat of reaction, gas temperature and the coal (solid phase) temperature. Also, it predicts the radial temperature profile inside the particles. The model includes a svstem of six differential eauations derived from the mass and enerzv balances for all phases at any point along the bed height and with% each particle. For the numerical solution, implicit collocation and relaxaiion techniques were used with finite differences for the time advance. Additionally, the model can be used to optimise the combustion process varying the excess of air, particle size distribution, coal type, geometry of the reactor, different types of ignition mechanisms and the velocity of the grate.

00100473 Operation management method of coke oven Nomura, S. and Kudo, T. Jpn. Kokai Tokkyo Koho JP 11 246,864 [99 246,864] (Cl. ClOB57/00), 14 Sep 1999, Appl. 1998/46,879,27 Feb 1998. 4. (In Japanese) The operation management method of a coke oven is presented. The manufacture of coke involves loading dry or preheated coal to the coke oven and setting a target pushing-out resistance during the discharge of

coke from the carbonization chamber to the pushing-out machine after coking. The temperature difference of the temperature of the combustion chamber to the temperature of the dry-preheated coal was used as an adjustment indicator.

00/00474 Optimization of combustion of industrial fuel gases in heating furnaces for rolling mills at Trinec Ironworks Kohout, K. Huin. L&y, 1999, 54, (6), 41-44. (In Czech) This review discusses methods for attaining optimum combustion parameters for a heating gas prepared by mixing blast-furnace gas, converter gas, coke-oven gas and natural gas.

00/00475 Pacification of FBC ash in a pressurized TGA Jia, L. and Anthony, E. J. Fuel, 2000, 79, (9) 1109-l 114. The high CaO content of FBC ashes causes difficulties with their management. The use of CO2 to recarbonate or pacify the ashes was suggested in order to increase the concentration of CaC03 in the ashes and decrease the amount of free lime. Work was performed using a Cahn 1100 pressurized TGA on coal and petroleum coke FBC residues at 0.1 and 111 MPa. Both hydrated and non-hydrated ashes were tested. Conversion of the CaO to CaC03 in non-hydrated ashes ranged from 9 to 27.4% while hydrated ashes showed conversion levels of 51.7-60%.

00100476 Pressure effect on char combustion in different rate-control zones: initial rate expression Lin, S-Y. er al. C/tern. Eng. Sci., 1999, 55, (l), 43-50. A fiied bed was used to study the effect of pressure on the initial rate of coal char combustion. Theoretical rate equations were used to analyse the results. Char particles of 0.25-0.5 mm diameter were combusted over temperature and pressure ranges of 559-1273 K and 0.1-1.6 MPa, respectively. Char combustion proceeded in first order with respect to oxygen. The combustion rate increased proportionally with pressure in the chemical-kinetics control zone (Zone I), exhibited a non-linear increase with pressure in the internal-diffusion control zone (Zone II) and was invariant with pressure in the external- diffusion control zone (Zone III). Theoretical rate equations involving explicit pressure terms were developed for predicting the combustion rate under elevated pressure. For given properties of char (d,, ,p= and k,) and operating conditions (C,, us,,,, T and P), the estimated combustion rate agreed well with the experimental results.

00100477 Pyrolysis - an alternative for combustion of municipal wastes Stelmach, S. and Sobolewski, A. Gospod. Paliwami Energ., 1999,47, (7), 17-22. (In Polish) An analysis of the pyrolysis process and possibilities for its use as a method for utilizing solid wastes is considered in this paper. The experimental results of pyrolysis of refuse derived fuel (RDF) are also presented. Comparisons are also made between pyrolysis and combus- tion of wastes.

00100476 Research developments in co-carbonization of coal and various additives Shen, J. er al. Meim Zhuanhua, 1999, 22, (3) 6-10. (In Chinese) This paper reviews recent coal co-carbonization technologies. The various additives used in this research include coal tar pitch, petroleum, a residue of coke petroleum and a hydrogneation residue. The study was performed in laboratories, coke-making plants and steel corporations all over the world. Co-carbonization technologies of coal with various additives prod to be an effective method for decreasing cost of coke making, enlarging-resources of coke making and improving coke quality.

00/00479 Research of composite propellants Florczak, B. Oraanikn, 1999, Pt. 1, 43-48. (In Polish) Composite propellants are researched in ‘this paper. The calorific values and burning rates are provided for the following propellants, ammonium perchlorate, aluminium powder, cyclotrimethylenetrinitra- mine, silver fibre and butylferrocene, with binders PBAN prepolymer and modified epoxyresin.

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00/00460 Role of thermophoresis in the deposition of fume particles resulting from the combustion of high inorganic containing fuels with reference to kraft black liquor Cameron, J. H. Goerg-Wood, K. Fuel Process. Technol., 1999, 60, (1) 49-68. In many manufacturing operation, such as that of carbon black and silica fume, the generation and deposition of fume are key processes. In addition to its role in these processes, fume deposition is an important phenomenon in the combustion of fuels containing inorganic com- pounds. One combustion process where fume deposition presents special problems is the burning of kraft black liquor. This paper presents a laboratory study of fume deposition with emphasis on the

Fuel and Energy Abstracts January 2001 49