296
MODERN GASWORKS PRACTICE
the refilling with coal in a single stroke. The first machine of this kind to be intro-duced was the Fiddes-Aldridge, wliicli accomplish.es the work by means of a specially designed push-plate conveyor consisting of two vertical parallel plates but with no bottom. These plates are hinged about every 3 or 4 feet, and are maintained in position by cross-bars arched to the same radius as the crown of the retort. Plates are suspended from the cross-bars, and are so arranged that when the conveyor or
Fig. 214.—The Fiddes-Aldridge Dischabging-Charger.
“ chain ” enteis the retorts the plates remain vertical, but are free to lift when the-chain is withdrawn. Each of the swinging plates pushes a certain amount of coal into and along the floor of the retort; whilst on the backward stroke the plates lift automatically and assist in levelling the charge. The construction and working of the chain will be clearly followed from Fig. 213.
A measuring chamber over the chain receives the coal from continnous hoppers, the coal being dropped through a shoot into the chain as the latter passes forward into the retort. The chain passes round a vertical polygon wheel, which is.