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In this paper the results of experimental studies of particle velocity fields in a circulating fluidized bed are presented. Measurements of particle velocity were carried out by means of a novel laser sheet technique, in which the laser beam was modulated with the help of an electronic modulator. Thanks to that, it was possible to register multiexposure pictures, called speckle-grams, which record single particle trajectories in selected areas of the flow. On the basis of this, three components of particle velocity vector can be estimated. [ABSTRACT FROM AUTHOR]

An analysis of the effect of thermal and flow conditions in the combustion chamber of the circulating fluidized-bed (CFB) boiler on the gaseous pollutant emission was undertaken in the study. The tests were carried out on a 670 MW boiler operating in the power engineering industry. On the basis of the obtained test results it was found that the optimization of primary and secondary air distribution, as well as fuel distribution, allowed the following pollutant reductions: CO by 52%, SO2 by 40% and NO by 6% in relation to the standard operation conditions of the boiler under investigation. The test results demonstrated that increasing the number of repetitions of bed material particle circulation between the combustion chamber and the recycling system resulted in an equalization of temperature distribution along the combustion chamber height and elongated the time of residence of sorbent particles in the CFB system. Ultimately, the test results showed the following pollutant reductions: CO by 71%, SO2 by 41%, and NOx by 19% with the number of particle circulation repetitions increased from 28 to 60 for the boiler analyzed. [ABSTRACT FROM AUTHOR]

The article presents the results of operational, numerical and experimental studies on windbox operating in a 235 MWe-power fluidized-bed boiler. The main problems of windbox design have been identified in the context of the problem of loose material backflow into the windbox space. [ABSTRACT FROM AUTHOR]