Temperature and pressure control of high temperature melt pump

　　The temperature control of the high temperature melt pump is mainly to check the side of the temperature. The temperature detection method: install a temperature sensor at the inlet of the high temperature melt pump to conduct real-time detection of the melt entering the melt pump, and operate the measured signal through the regulator with PID self-tuning, and output a standard current of 4-20mA to control the solid-state power string control device, so as to change the power of the heater to constant temperature The control effect can keep the material temperature at the value required by the process. As for the materials flowing out of the melt pump body, the temperature will also change due to the material delivery and pressure of the gear pump, so a temperature sensor is added to the part near the discharge port to check the side, and then the measured signal is processed by the regulator with PID self-tuning to output 4-20mA standard current to control the solid-state power control device, so as to change the power of the tracing band, To achieve the effect of constant temperature control of melt pump.

　　The specific scheme of high temperature melt pump pressure detection is to add a pressure detection sensor in front of the melt pump to detect the incoming pressure of the extruder, transmit the signal from the sensor side to the display instrument through the signal cable, and express it intuitively in digital form. For the outlet pressure of high temperature melt pump, the method of pressure control is to install pressure detection element at the outlet of melt pump, and transmit the measured pressure signal to the PID self-tuning controller for display by cable. The controller controls the deviation value by comparing with the preset value, and then outputs 4-20mA standard current signal to the frequency converter to control the motor speed, so as to achieve the function of pressure control.