Modern Gasworks Practice

144 MODERN GASWORKS PRACTICE generally laid, the blocks provide for admixture taking place very nearly at right angles. A simple and efEective means of providing for a more parallel flow is to split a 9-incli firebrick diagonally, and to insert it under the final blocks each side as shown, so that the latter are given an upward cant. The method will be clearly followed from the sketch. It is interesting to recall h.ere that the flame development takes place quite differently in vertical retort firing. In this case the flame follows a spiral course from below upwards (in the Glover-West and Intermittent systems), or from above downwards (in the Woodall-Duckham system). The latter arrangement provides for the heating of the upper third of the retort by a number of burners, whereas the lower portions of the charge are situated in a comparatively cool zone. In the Intermittent system the regulation of the flame development is extremely well effected by means of brattices which ensure the gas streams taking parallel courses, whilst at suitable intervals mixing blocks are inserted which thoroughly churn up the inflowing air and gas.