Polyester melt viscosity control system and control method thereof

Abstract

The invention designs a polyester melt viscosity control system, mainly including a vibration-typed viscosity meter, a signal input unit, a control unit, a signal output unit and an actuator; the actuator is arranged on a polyester pipe; the vibration-typed viscosity meter is connected with the signal of the signal input unit; the signal output unit is connected with the actuator signal; a pressure detector is arranged on the polyester pipe; and the pressure detector and the vibration-typed viscosity meter are connected with a viscosity revising unit by signal. The control method of the control system adopts the viscosity signal of the melt in the polyester pipe which is detected by the vibration-typed viscosity meter and the pressure signal which is detected by the pressure detector as the detection signals, corrects the viscosity signal which is detected by the vibration-typed viscosity meter by making use of the relationship between the pressure and the viscosity in the polyester pipe, and uses the revised viscosity signal as a control signal to control the system; and the correction is carried out by a formula V=(1+K*((P-P0) / P0)) V (detection viscosity). The invention effectively eliminates the influence of the pressure fluctuation in the polyester pipe on the measurement of a viscometer.

Description

technical field [0001] The invention relates to chemical fiber equipment and its control method, in particular to a polyester melt viscosity control system and its control method. Background technique [0002] At present, the most important quality control parameter in the production of polyester in the chemical fiber industry is viscosity. The quality of viscosity control largely determines the quality of products, which puts forward high requirements for polyester viscosity detection. The vibration viscometer is only in contact with the melt through the probe, and the amplitude is extremely small, which will not affect the quality of the melt and is not easy to be damaged. Therefore, most online viscosity measurements use the vibration viscometer as a detection tool. But this kind of oscillating viscometer is very susceptible to the influence of melt pressure, and the change of pressure will easily cause the deviation between the measured value and the actual value, especi...

AI Technical Summary

Problems solved by technology

But this kind of oscillating viscometer is very susceptible to the influence of melt pressure, and the change of pressure will easily cause the deviation between the measured value and the actual value, especially the increase of melt pressure during the melt filter switching cycle will make the detection of the viscometer more accurate. If it is not allowed, it will not only bring great inconvenience to the production process control, but also seriously affect the product quality, and sometimes even make the product fail to meet the process requirements, resulting in great waste

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