Fig. 101.—Power-driven Revolving Distributor.
Automatic Travelling Distributors.—There are several types of these on the market at present. The first is manufactured by Messrs. Birch Killon and Co., [Fig. 102], and is constructed on the Fiddian water-wheel principle. The design is similar to that described in connection with the automatic revolving distributor, but it involves two rail tracks supported on walls or piers on each side of the filter. The head required for this type is about 2 feet from the surface of the filter to the top water level in the carrier, and the distributor is fitted with a syphon which feeds it from the carrier or trough. In large schemes the trough is placed along the centre of the filter, and supplies a separate distributor on each side.
Fig. 102.—Fiddian Travelling Distributor.
Another type is manufactured by Messrs. Ames Crosta Sanitary Engineering Company, as shown in [Fig. 103]. This sprinkler can be adapted to existing contact beds. It is carried from the walls of the central channel in cantilever form, no other bearing or rails being required. On each side of the machine a hopper is carried in which water-wheels revolve. The water in its passage from the feed channel to the distributing arms is conveyed on to the water-wheels, and the power generated there is transmitted by means of a chain drive to the wheels of the carriage, and thus the whole apparatus is moved along the beds. When the machine nears the end of the bed a reversing lever comes in contact with a buffer, and by this means the direction of motion is changed, and the machine travels backwards along the bed. Two distributing arms are carried on each side of the apparatus, one feeding half the bed in one direction and the other feeding the remaining portion of the bed in the opposite direction, thus giving a regular intermittent feed to the bed. A great advantage of this class of machine is that the whole of the machine is supported from the central channel, and as the wheels are close together, the long lengths of shafts with their risk of twisting, retarding and wearing are dispensed with.
Fig. 103.—Travelling Distributor.