| 摘要 |
A wash box for separating materials produced in, for example, a mining operation, into fractions of different densities. The machine is divided vertically into compartments, including at least one stratification compartment and at least one reject compartment, the raw material being delivered onto the grid, the level of water in the compartments being higher than the grid. Vertical pulsations are applied to the water in the compartments, causing the water to travel through the perforations of the grid, to stratify the material on the grid, while movement of the water through the wash box tends to carry the lighter fraction from the wash box. The pressure which pertains in the stratification compartment is continually monitored, such as by the use of a beam, emitted into a stand pipe connected to the stratification compartment, and which is reflected by the surface of the water in the stand pipe, the time taken for the beam to travel from the emitter to a receiver being used to produce an output signal, dependent upon the pressure pertaining in the stratification compartment. This continual monitoring is advantageously used to control the pulsations applied to the adjacent reject compartment, controlling the rate at which reject material falls over the edge of the grid, but may be used to advantage in the general control of operation of the wash box. Alternatively or in addition, separate conveyor means are provided, at differing vertical levels, for removing the reject materials of smaller size, which pass through the perforations of the grid, and the reject materials of larger size, which pass over the edge of the grid. Such an arrangement is particularly advantageous where the wash box is a compound wash box.
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