| 摘要 |
A device for controlling the flow of foam for use in separating mineral particles from ore wherein an expandable container (9) receives foam at the rapid flow rate of a foam generator until the expandable container is substantially full of foam and then to dispense the foam at a lower flow rate by applying a pressurized gas to gradually push the foam out of the container. The container may be defined by a bellows or a cylinder (10) variable in volume by a piston (12). In operation foam supplied by a generator (8) flows into the container (9) through an opened solenoid valve (32). As the container fills with foam, gas previously admitted to a chamber (11) is discharged through a solenoid valve (36) until the container is filled, at which time a switch (40) is actuated. The switch causes the valves (32, 36) to close and a valve (34) to open so that pressurised gas from a source (22) collapses the container and expels the foam through a nozzle (50). <IMAGE> |
