Abstract :
This paper consists of a review, expressed in fundamental terms, setting forth the past development, the present position and the trend of progress as applying to pulverized-fuel firing and stoker firing. The relative positions of pulverized fuel and stokers, and of the ¿bin and feeder¿ system and the ¿direct fired¿ system, of pulverized fuel, are described in detail. The considerations governing the development of plant arrangement and of individual items of equipment entering into pulverized-fuel systems are discussed in the light of accumulated experience, the shortcomings and virtues of past designs being set forth with equal frankness. The combustion process in its relation to coal preparation and furnace and burner design is considered, and also the history of the pulverized-fuel furnace, beginning with solid refractory walls and terminating with the water-cooled and steam-cooled furnace. Improvements in stoker design and performance, and the necessity of improving stoker furnaces so as to meet modern requirements of rating, efficiency and preheated air temperature, also the factors defining the field of application of travelling-grate and retort-type stokers, are dealt with. Finally, a brief discussion of the problem of ash and grit discharge from the chimney and of its solution is included.
