摘要 |
<p>PURPOSE:To improve treated water in reduced power consumption and to facilitate maintenance by setting the frequency for controlling a blower outputted from an inverter so as to change over the same to at least two stages in connection with the OFF-and ON-states of a filth pump. CONSTITUTION:A filth pump 2 is operated and stopped by the ON- and OFF- signals of the level switch 1 mounted in a flow rate control tank 8. When the filth pump 2 is in an OFF-state, an inverter 4 controls a blower 5 at preset frequency X1HZ. When the filth pump 2 becomes an ON-state, the frequency of the inverter 4 is changed over from X1HZ to X3HZ and further changed over to X2HZ after the elapse of a T1-time. By this method, the blower 5 is operated at the frequency X2HZ for a T2-time until the filth pump 2 is turned OFF but again operated at frequency X3 when the pump 2 is turned OFF.</p> |