The Mechanical Handling and Storing of Material

64O the mechanical handling of material The coal (small) is delivered in barges alongside the filler pit, situated under the ash tower, and is shovelled by three or four men direct from the barges into a longitudinal receiving hopper, at the rate of 4 to 5 tons per hour per man, costing about 2d. per ton in wages. From the receiving hopper the coal is delivered by the filler into the conveyor buckets passing beneath. It is then carried inwards, ascending to the upper strand over the bunkers, where it is automatically dumped at any desired point. The buckets, after being dumped, descend and return under the boilers, receiving the ashes by shovelling directly from the ash pits. They are then carried outwards, towards and over the ash hopper where they are dumped, and descend to the filler pit again to be charged with coal. The ashes can be retained in the hopper until convenient times for discharging, which operation can either be effected into barges or carts as desired. The motive power is supplied by an electro-motor of the British Thomson-Houston enclosed type, which is geared directly to the countershaft of the conveyor. This installation is the work of Messrs Babcock & Wilcox, Ltd. Coal and Ash Handling Plant of the Powell Duffryn Steam Coal Co., Aberaman, South Wales.—Figs. 896, 897, and 898 show a system of overhead bunkers and the conveyor for serving them. The first half of the plant was supplied in 1906 by Messrs Babcock & Wilcox, and the extension half two years later. The arrangement is quite evident from a study of the illustration, and is in accordance with the general practice in such installations, the coal being delivered by wagons into a receiving hopper, and the conveyor taking the coal from there by means of a filler, elevating, and carrying it horizontally above the overhead bunkers, and delivering into any section as required. From these bunker divisions the coal is delivered by means of special valves and chutes into the stoker hoppers. Ashes are dealt with by the same conveyor, being delivered into an ash bunker outside the main building, and taken from thence by carts or other conveyances. The normal capacity of this conveyor is 40 tons of coal per hour, but it can be increased economically to 50 tons if necessary. Coal-handling Plant and Store at the Buenos Ayres Grand Central Electric Power Station, Argentine Republic.—Fig. 899 represents a system of coaling boiler-houses direct from steamers or barges alongside the wharf. Two: gantry cranes, travelling parallel with the wharf, are capable of taking by means of grabs 1 ton charges of coal from the steamers or barges, delivering it into conveyors—carried on the horizontal girders of these gantry cranes—which in turn deliver the material into either one or other of a pair of conveyors marked b and b1 on plan. These conveyors run in opposite directions, and both discharge over another pair of conveyors marked c and c1 running at right angles to them. The conveyors b and b1 are the patent tipping tray type (described on page 108), and have at certain times the further duty to perform of collecting coal from railway wagons underneath. Two travelling cranes are carried by the gantries supporting these conveyors, which collect material from railway wagons on the ground line and deliver it into hoppers, to which they are yoked, these hoppers delivering the coal, and regulating the quantities, into conveyors b and B1 which again deposit into conveyors c and c1. These latter conveyors both deliver into and collect from the coal silo, but before being delivered into the silo the coal is broken and weighed automatically in its transit from conveyors B and b1 to c and c1. In discharging from the silos conveyors c and c1 deliver into two other conveyors d and d1, travelling in a similar manner to b and B1, in opposite directions to each other, and delivering, therefore, right or left according to requirements. These conveyors