THE PRELIMINARY PURIFICATION OF COAL GAS 517
and is so arranged that either the whole or only one-half of tlie machine may be used at one time. In its later form it is driven from the centre of the shaft, and by withdrawing the coupling bolts one-half of the shaft only is re-volved. The scrubbing appliance differs from that in otter machines in that it consists of a number of brushes made from foreign bass and attached to a framework carried from the central shaft. The gas in passing from bay to bay finds a path between the bristles of the brushes and is, accordingly, subjected to most intimate contact with. the liquor.
Clapliam’s “ Eclipse ” washer-scrubber was one of the first to be introduced and is still in common use, although some modification has taken place as compared with the original machines. It is particularly of interest in. view of the unique means employed for bringing the crude gas in contact with wetted surfaces. The outer case is not cylindrical, the lower portion being rectangular and the upper half semi-circular. The shell, as in other machines, is divided into a mimber of compartments in which cylindrical cases (made from cast iron) and having per-forated back and front plates, revolve. These cases, which vary in number from 8 to 12, contain several compartments, all of which. are filled with wooden balls. The balis are kept
s o
m position in the cases by means
’est Cocl
Fio. 321.— Whbssoe Washbr-Scbubber.
of sheet-iron cover plates arranged round the