When the agitator is started at rest, the better the impeller overcomes its own inertia, the overcoming of the inertia of the liquid pushed by the impeller and the friction of the liquid. At this time, the relative inclination of the impeller and the liquid is large, and the impeller is subjected to the action area of the liquid resistance, so the required power value is inevitably large, which is the starting power of the so-called agitator.
When the agitator is operated under full baffle conditions, it consumes a large amount of motion power, which is approximately equal to the agitation power at the critical Reynolds number Re from the turbulent to laminar transition point, and it is considered that this power value is almost the same as the start of the agitation. The power is equal, and this view can be attributed to the fact that the starting power and the operating power are approximately equal. At start-up, the motor relies on the torque margin to accelerate the liquid and the agitator to a stable operating speed without causing the motor to overheat or fail to start. Therefore, it is not necessary to start the power when selecting the motor, but the operating power can be used as the starting point for selecting the motor power, and the power loss in terms of the transmission mechanism and the sealing mechanism can be considered.