461,976. Washing granular materials. TATE, F. R. (Wilmot Engineering Co.) Aug. 26, 1935, No. 23865. [Class 82 (ii)] Granular material, e.g. coal, is washed in an apparatus comprising a separating compartment having a perforated bottom through which an upward current of liquid is passed, the lighter particles being discharged over a baffle wall at one end of the compartment and the heavier particles through a discharge opening adjacent one end of the perforated bottom. Gate means for controlling the discharge through the opening and means for positively removing the particles passing through the opening are provided, the gate means and the removing means being operated by a motor which is started and stopped intermittently and automatically in accordance with the increase and decrease in the amount of refuse on the perforated bottom, for example through the medium of a float in the refuse compartment which communicates with the separating compartment through the discharge opening. The refuse removing means may be a conveyer or a rotary valve and a conveyer in combination. In the form shown in Fig. 1, the material is fed from a hopper B past an adjustable gate C to the separating compartment A. The water supply chamber beneath the perforated bottom D is divided into two or more compartments 10, 11 each provided with a valved supply pipe for water under pressure, so that the flow of water through different areas of the bottom can be controlled. The lighter constituents pass over a baffle wall E to discharge troughs F. The heavier constituents pass down the bottom D to a discharge opening G controlled by a gate H movable in guideways 18. A rotary vaned member 31 receives material passing through the opening G and discharges it on to a guide plate 34 which leads it to a conveyer J. The member 31 and the conveyer J are driven by chain-andsprocket gearing from an electric motor Q. A float S in the refuse compartment, which rises and falls as the amount of refuse on the bottom D increases and decreases, operates a switch R which starts and stops the motor Q. The motor Q also actuates the gate H through a governing device 25, a link 23, and a bellcrank lever 20, so that when the amount of refuse in the separating compartment A increases the motor is started, the refuse removing means comprising the member 31 and the conveyer J are set in motion, and the gate H is raised gradually as the motor gains speed and operates the governor. In the form shown in Fig. 6 the water tank below the separating compartment has a single water supply, a baffle 40 being provided to produce an even flow. The refuse gate means comprises a gate H with a rearwardly directed flange 54, the gate being raised or lowered by means of a hand wheel 53, and an auxiliary gate 55 which is hinged to the lower edge of the gate H and is actuated by the motor Q through the governor, links, and a bell-crank lever. The refuse removing means consists of the conveyer J which is arranged close to the opening G1, the intermediate rotary member shown in Fig. 1 being omitted. In the form shown in Fig. 8, the opening G is regulated by a hand-operated gate H and a gate 64 pivoted to the lower edge of the baffle wall E and operated by the motor Q. The gate 64 may be connected to the baffle wall by a pair of substantially parallel links. A plurality of the separators may be used in series, the lighter constituents from one separator being passed to the next along a dewatering trough, the water from the troughs being collected in a tank from which it is pumped to an overhead tank from which is led a supply pipe with branches leading to the several separators. Specification 338,887, [Class 82 (ii)], is referred to.