The role of the intensive mixer is to transform blended powder or recycled material into a gel-like substance by continuously rolling and pressing with two rotors under heat. The working process of the intensive mixer involves first conducting intensive mixing with the raw materials, then discharging the processed materials. After a period of time, the materials are reloaded. The motor only performs work during the addition and discharge of materials. It does not work after discharge and before the next reloading. However, the motor remains running throughout this process, resulting in a significant waste of electrical energy between discharging and the next reloading.
Frequency Conversion Energy-Saving Retrofit Plan: Adjust the motor with a frequency converter, where the motor operates at 50Hz rapidly during the processing stage. During periods without processing, reduce the frequency converter's frequency to maintain it at 35Hz (the operating frequency can be set), thereby slowing down the motor speed to achieve environmental protection and energy-saving goals.
To ensure ease of use for the kneader after the energy-saving project, the following control measures were selected: After the kneader is fed, the load increases, causing the motor speed to rise. During standby, the load decreases, and the current will drop (remaining within the range of no-load current). By utilizing this characteristic, the speed of the variable-frequency drive is determined through its built-in current detection function.
The A1V terminal and AI2 terminal of the inverter are connected. The A1V terminal serves as the digital signal for the inverter's output voltage (matched to 0-10V with 0- rated current value). Upon site inspection, the inverter draws 200A at full load, at which point the A1V output is 4V (adjustable as needed based on actual conditions). The current exceeds 200A after the addition of material. At this point, the AI2 terminal voltage from 0-4V is matched to a power frequency of 35Hz (with the lower limit frequency set to 35Hz), and from 4-10V the power frequency is essentially 50Hz. The A1V determines the power of the analog input signal based on the load current, while the AI2 adjusts the inverter's input frequency by transforming the power of the analog input signal from A1V, achieving the effect of changing the motor speed.
