The Mechanical Handling and Storing of Material

23° THE MECHANICAL HANDLING OF MATERIAL Fig. 314. Arrangement of See’s Hydraulic Ash Ejector. Fig. 315. Arrangement of See’s Ash Ejector to serve two Stokeholds. York, and his system is shown by Fig. 314. On the floor of the stokehold is fixed a hopper a, fitted with a water-tight lid B, and fastenings g h. The hopper A is joined to the ejector pipe c, at the bottom of which is a hydraulic nozzle f, regulated by cock e, and fed by the pressure main d. Pipe c is bent at its upper end and delivers its load overboard above the water line; it is also fitted with an air valve i, through .which air may be admitted during the conveying action, and a cock c for emptying the water out of the apparatus after use. The ejector works as follows : After the cocks and valves c, e and i have been closed, the lid b is opened and the hopper a filled with ashes; the pressure pump is now started. As soon as the gauge indicates the required pressure, the cock e is opened quickly and the water under pressure enters through jet f at a high speed and forces the ashes through pipe c overboard. At the same time, tap I is opened to admit air, which acts like an injector in dispersing the ashes. If the coal has a tendency to cake and the ashes contain large pieces of clinker, a grating is placed on top of the hopper and the large pieces are broken with a hammer, so as to prevent the choking of the pipe c. But this has the drawback that, unless the pressure gauge is carefully watched and the cock opened at the exact moment, the pipe D or the pump might be injured; so the same inven- tor has added an automatic device to prevent this. In this scheme the jet nozzle is closed by a rod which carries two pistons of different diameters, and a spring also holds this rod in position. The whole is en- closed in an iron cylinder which communicates with a branch pipe from the hydraulic main. As soon as the right pressure in the main is reached, the valve opens automatically and the ashes are ejected. When the ashes have been disposed of, a three-way valve is so set as to permit the water to escape in front of the piston, when the nozzle will automatically close. Generally, one ejector is used in connection with each stokehold; but the inlet can also be duplicated to serve two stokeholds, as shown in Fig. 315; f f are the two lids of the hoppers a a, and are so con- nected by a chain h that only one can be opened at however, several obvious disadvantages. As there is always a tendency for the finer ashes the hopper, where they are out of reach of the water jet, Thorne has constructed a hopper as shown in Fig. 316. This permits a portion of the water from the hydraulic main h to pass through a narrow channel g into the hopper, and thus keeps it clean. The amount of water so used can be adjusted by the valve/ Another method is that of Hochstein, shown in Figs. 317 and 318. It is for a a time. This construction has, to accumulate in the bottom of