| 摘要 |
PURPOSE:To prevent a blockade between a cyclone and a hopper, by controlling the rotational speed of a rotary feeder for controlling the extraction amount of powder from a hopper, in accordance with the level of the powder in the hopper to make the level of the powder uniform, and by controlling the amount of purge gas. CONSTITUTION:A cyclone 2 separates polymer powder from carrier gas. The carrier gas is then taken out through a line 7 while the polymer powder is accumulated in a hopper 3. At this time, a level meter 8 detects the level of the polymer powder in the hopper 3, and therefore, a rotary feeder rotational speed control system 15 controls the rotational speed of a rotary feeder 5 to maintain the level of the powder constant. Further, when a blockade occurs between the cyclone 2 and the hopper 3 so that the level of powder lowers and therefore, the rotational speed of the rotary feeder 5 lowers below a predetermined value, the control systems 9, 10 increase the opening and closing cycles of the valve, and therefore, the amount of purge gas is increased to aim at eliminating the blockade. With this arrangement it is possible to prevent blockade. |
