| 摘要 |
PURPOSE:The avoid the surging limit and to eliminate the unnecessary air discharge, by adding a signal controller which sets the surging limit to an output signal commanding the opening control of a suction valve. CONSTITUTION:The target air flow value 1 is applied to an air flow controller 2 to be compared with the value detected by a sucked air flow detector 7. If a deviation exists between both input values, the controller 2 increases or decreases the opening command output value to a suction valve 6. A signal limiter 3 delivers an opening command to keep the surging limit value to the valve 6 although the opening command output value of the controller 2 is set at the levels other than the surging limit. At the same time, the value 1 is supplied to a comparator 8 along with the value detected by a supply air flow detector 11. In case the value 1 is smaller than the output of the detector 11, an opening command is delivered to a control circuit 9 of a wind discharge valve 10. While a closing command is delivered when the value 1 is larger than the output of the detector 11. |
