Abstract
A general theory of pneumatically transporting industrial coals through pipework is proposed based on an adaptation of Hinkle's general equation for solids flow in pipework. The theory is suggested as an overall mathematical framework for designing systems for industrial and power station coal-fired plant and possibly for general transportation systems. Results are given for trials on a test rig based on three industrial coals—singles, dry/untreated and wet/washed smalls coal—and their fit with results predicted by the theory. In the design of the system, I propose the concept of dividing the system into three basic sections: (1) the clean-air section; (2) the coal-transportation section; and (3) the ash-transportation section. Equations are given for designing sections (1) and (2) and empirical data for section (3). Curves are given for the coal transportation section showing the effect of the coal concentration in the pipework, the pipework diameter and length and the verticality of the pipework on the dependent variables—pressure loss, coal quality, power requirements, energy consumption, flow rate and average pressure in the section. Important general conclusions are drawn from this work and practical information is given based on my experience. It is finally suggested that there is an urgent need for new concepts in the design of automatic systems for all types of coal-fired plant if coal is to assert its natural place in the current explosion in demand for world energy. I suggest that automatic systems are the best way of achieving this.
Get full access to this article
View all access options for this article.