| 摘要 |
<p>PURPOSE:To save the energy of a blower operation by controlling blowers to 3 stages; low, middle and high speed revolutions in order to maintain a DO(dissolved oxygen) value within upper and lower limit values by utilizing a DO sensor with upper and lower limit alarms mounted in an aeration tank. CONSTITUTION:The DO value in the aeration tank 1 is measured by the DO sensor 2 with the upper and lower limit alarms and is sent to a DO sensor body 3. The blowers 5 are controlled in revolution at a certain specified revolving speed (middle speed) by an inverter 4 while the DO value exists between the upper and lower limit values preset in the DO sensor body 3. An upper limit alarm signal is outputted from the DO sensor body 3 when the DO value exceeds the upper limit value. The inverter 4 lowers the revolving speed of the blowers 5 by this signal. The blowers 5 are similarly revolved at the high speed when the DO value falls below the lower limit value. The revolving speeds of the blowers are thus controlled in three stages by load fluctuations and, therefore, the rate of saving the energy is improved.</p> |
