Method and device for controlling conical twin-screw extruder

Abstract

The invention discloses a method for controlling a conical twin-screw extruder. The method comprises the following steps of: S1, setting a conventional current signal and a current deviation value; S2, collecting current signals of a main motor of the conical twin-screw extruder; S3, comparing the collected current signals with a set normal current signal so as to obtain a deviation current; and S4, outputting the deviation current as a signal, and controlling the rotating speeds of the main motor, a feeding motor and a traction motor of the conical twin-screw extruder, wherein when the current of the main motor of the extruder is increased suddenly and deviated from the set deviation value, the speed of the main motor is reduced, and the speeds of the feeding motor and the traction motor are decreased in proportion; and conversely, when the current of the main motor of the extruder is decreased suddenly and deviated from the set deviation value, the speed of the main motor is increased, and the speeds of the feeding motor and the traction motor are increased in proportion. According to the method, through detecting the current mutation of the main motor of the conical twin-screw extruder, the current is operated, and after operation, the speeds of the main motor, the feeding motor and the traction motor are changed, and the main motor is kept running at a same torque. Therefore, various interference problems such as non-uniform blanking and the like causing the current changes of the main motor are solved. The invention also discloses a control device using the method.

Description

technical field [0001] The invention relates to the technical field of plastic processing, in particular to a control method and control equipment of a conical twin-screw extruder. Background technique [0002] Conical twin-screw extruder is a common equipment in the plastic manufacturing industry, such as the extruder disclosed in the patent number 201110094947.X. [0003] At present, in the entire extruder industry, there are mainly two types of controls for conical twin-screw extruders. 1. Control the start-stop and running speed of the extruder main engine, feeding motor and traction motor through a simple electrical circuit; control and adjust the temperature of the main engine barrel and mold through the temperature control table. This control method has low cost, but when the production speed is to be increased or decreased, the synchronous control effect is not good, and the product quality is easily affected. 2. The start-stop and running speed of the extruder hos...

AI Technical Summary

Problems solved by technology

However, PVC powder has various reasons such as uneven feeding and different material specific gravity, which can easily cause sudden changes in the screw torque, which can easily cause uneven thickness of the pipe product; even the motor has not reached the rated torque, causing the screw to break.

Neither of these two control methods can effectively solve the above problems.

Images