THE MECHANICAL HANDLING OF MATERIALS 295
Dbake’s Projector and Pusher
Drake’s stoking machine, in which. the projector and pusher are mounted on a common wheel-base, is illustrated in Figs. 210 and 211. The principle of the projector dillers entirely from that of De Brouwer. The outer casing contains a rotor very similar in construction to the paddle-wheel of a steamer, with the exception that it is divided down the centre so that with a feed at either side the coal is charged into the retort in two streams. These streams converge in the retort and form the charge. Owing to the manner in which the coal feed is arranged the lumps of coal are not knocked into the retort by the blades of the rotor, but they are picked up and thrown in by a centrifugal force. It will be seen that the coal drops from a storage hopper direct into a telescopic shoot, which. in turn delivers to a breeches shoot feeding into both. sides of the projector simultaneously. An apron is fitted to the front of the casing in order to prevent any spilling of coal.
The construction of the discharging pusher will be readily followed from Fig. 212. The ram is of taper construction, and the narrow end lets down into the wider end when folding round the drum. The chain is constructed from mild Steel, and the links are fitted with. renewable hard steel sliding pieces and hard steel horns. To one side of the skaft of the main drum is keyed a phosphor-bronze machine-cut worm wheel driven by a mild-steel worm running in an enclosed oil-bath.
Fig. 213.— The Fiddes-åldridge “Chain.”
Discharging Chargers
One of the most interesting modem developments connected with the operation of gas retorts is the discharging charger, which effects the expulsion of the coke and