The stirring speed of the reactor needs to be connected to the DCS; how then can the stirring speed be monitored?

1. Is the stirring speed controlled through the current feedback of the stirring motor? The current cannot be used to determine the rotational speed, as at the same current level, the corresponding rotational speeds under heavy load and light load are different. 2. For motors whose speed cannot be adjusted, how is the rate calculated? For motors for which it is not possible to measure the rotation speed, an encoder is generally added – one is installed on the reducer – and Hall elements or infrared elements (usually Hall sensors, which are resistant to dirt) are used to measure the mixing speed. 3. If one only needs to determine whether the mixing motor is good or bad, what is the most reliable measuring instrument? It is only necessary to check the condition of the mixing motor; the simplest method for this is to use a three-phase ammeter (or transmitter). As long as the currents in all three phases of the motor are equal and the motor current remains below the rated value, it can be determined that the motor is working properly.

Using a phase sensor or encoder to measure rotational speed is a well-established approach

By directly measuring the rotational speed of the shaft, it can be done. Three reed switches; for less than 10 yuan more, you can get other components as well. A friend can write a small program to control the rotation speed

This post was last edited by liuyun001 on 2019-6-13 at 14:15. Proximity switch + pulse frequency conversion module: 1. Proximity switch: A protrusion on the shaft is used (or a few can be welded on if none is available); as this protrusion approaches the proximity switch, a pulse signal is generated； 2. The pulse signal generated by the proximity switch is fed into a pulse signal frequency conversion module to be converted into a standard signal. 3. Pulse frequency ÷ number of pulses per week = rotational speed

Is the motor in your home exposed, without any protection? Just connect a fault output and that’s it

1. Current cannot be used to detect rotational speed. 2. I remember that previously a colleague wanted to measure the rotational speed of a shaft; since there was no frequency converter, the solution I suggested was to transmit the data remotely to the DCS. A bolt or something similar could be welded onto the shaft, and a proximity switch placed outside the shaft. The DCS could then be used to count the rising edges of the DI signal, and by dividing this by time, the rotational speed could be determined. I hope it’s inspiring to you. 3. The current of the motor can reveal many issues related to it; a current transmitter can be used for current monitoring. If an emergency stop of the motor is required, the DCS’s DO output can be used to send a signal to the motor’s start circuit.

1. Current indeed cannot accurately reflect the rotational speed. It can only reflect the consistency of the material. 2. For motors whose speed cannot be adjusted, it’s simply the speed indicated on their nameplate, divided by the reduction ratio of the gearbox to calculate it. 3. The most reliable method, of course, is to use devices such as motion sensors on-site for detection.

Depending on the different reaction stages, or in case of abnormal operating conditions that result in the formation of highly viscous fluids, the stirring current can increase significantly, leading to motor damage; this serves as a reminder for operators to be cautious. . . Furthermore, in the event of sudden abnormalities, to prevent heterogeneous reactions and local overheating that could lead to an expansion of the accident, stirring must not be stopped; instead, the stirring condition must be monitored.