On the influence of coal-dust in colliery explosions. No. III

Abstract

In September of last year (1880) I commenced a new series of experiments with coal-dust with a larger apparatus than the one described at p. 416, vol. 28 of the “Proceedings.” Excepting, the difference of scale, however, the two sets of apparatus are nearly the same in construction, and they are identical as far as the experiment is concerned. A photograph accompanying the paper, and remaining in the hands of the Royal Society, represents the apparatus as it stands ready for work at Llwynypia Colliery. Its principal details may be sufficiently understood from a verbal description; they are as follows:— A. The explosion chamber, about 6 feet long by 2 feet in diameter; lined with thin strips of wood round about its circumference; with two openings, a and a ', in its upper side, the first for admitting firedamp, the second for igniting the mixture; a third opening nearly below a ' for letting out the air displaced by the fire-damp is not visible. Internally it is provided with a small centrifugal fan, which draws the air and gas from the farther end of the cylinder through a pipe 4 inches in diameter, and concentric with the cylinder, and ejects it round its periphery at the nearer end, where it is situated. This mixes the air and gas. The cylinder rests on a carriage with wheels, and can be drawn back from or brought close up to the rectangular chamber, B, to which it can be fastened by means of four bolts.