| OCR Text |
Show -2- The first of these concerns the combustion of pulverised coals in general, but with an emphasis upon NO emission control with x otherwise improved corrbustion. The emphasis presently is upon the air staging technique and experiments are being conducted at the semi-industrial scale in boundary condition simulating water tube boiler combustion chambers. In addition, appropriate back-up fundamental research is being executed. Such programmes have been ongoing for a number of years but a particular emphasis has been introduced recently in connection with the development of a better understanding of the relationship between coal properties and the combustion process. A second area of research which was initiated in 1980, concerns that of the control of sulphur dioxide emissions through the injection of appropriate sorbents in or adjacent to the flame. This is very much related to the first area mentioned above and together they are particularly important in relationship to the control of the international problem of acid rain deposition. The third area is one in which considerable progress has been made and concerns the firing of the so-called "off-specification" fuels which include as examples, coal in water slurries and petroleum residues, the latter in some cases, in combination with natural gas. This field covers a wide range of specific objectives and industrial applications, but a common point is one of determining optimum burner design parameters for the efficient combustion of these fuels taking into consideration variations in the fuels' quality. Finally, a research programme was initiated in 1982, which forms a fundamental basis to the burner design aspects of the other three areas of research. This concerns the development of a quantitative understanding of the effect of burner and combustion chamber variables upon the aerodynamic flow stream structures developed in the "near field" of swirl stabilised burners, i.e. in the region |
