| 摘要 |
PURPOSE:To carry out the surging preventing control and released wind operation control by one wind releasing valve by setting a plurality of surging preventing lines and opening closing-controlling the wind releasing valve at a plurality of operation speed, in a blower equipped with the wind releasing valve for adjusting the discharge wind pressure. CONSTITUTION:The suction wind quantity measured by a suction wind quantity meter 6 is set as the second stage surging preventing pressure B corresponding to the suction wind quantity at that time point, by a kinked line calculator 11. Further, the set value S for calculating the first stage discharge wind pressure is subtraction-calculated in a calculator 12, and the result is set as the first stage surging preventing pressure A. When the discharge wind pressure measured by a discharge wind pressure meter 8 becomes equal or more than the second surging preventing pressure B, a state signal C is outputted from a signal comparator 16. While, a surge preventing adjuster 13 automatically opening/closing-operates a wind releasing valve 5, having the first stage surging preventing pressure A as aimed control value. At this time, a signal selector 15 is selected by the state signal C, and the normal and high speed set values K1 and K2 are selected.
|
