Components of extrusion equipment
An extrusion equipment is usually composed of main machine (extruder), auxiliary machine and its control system. In general, these components are collectively referred to as extruders.
1. Host computer
The main machine of an extruder is composed of extrusion, transmission, heating and cooling systems. The extruder is mainly composed of screw and barrel;
The drive system is used to drive the screw, to ensure that the screw has the required torque and speed in the working process; the heating and cooling system is mainly used to ensure the temperature control of materials and extrusion system in the molding process.
2. Auxiliary equipment
The composition of the auxiliary machine of extrusion equipment depends on the type of products. Generally speaking, the auxiliary machine is composed of agent permeating and setting device, cooling device, traction device, cutting device and product coiling or stacking device.
3. Control system
The control system of extruder is mainly composed of electrical appliances, instruments and actuators
(1) Control the driving motor of the main and auxiliary machines, meet the speed and power required by the process requirements, and ensure the coordinated operation of the main and auxiliary machines.
(2) Control the temperature, pressure, flow rate and product quality of main and auxiliary machines
(3) Realize the automatic control of the whole unit.
Control of traditional screw extruder
1) In the traditional screw extruder system, the screw is driven by DC motor. In the case of direct transmission, the screw is directly driven by the gearbox; in the case of indirect transmission, the screw is driven by belt and traction plate. The traditional DC motor itself has some shortcomings: for example, the carbon brush of DC motor needs to be replaced once a quarter, and the commutator spark of DC motor increases in dusty or corrosive environment. Cause abnormal operation.
2) The disadvantages of indirect drive screw extruder are: there is belt slip, which will cause a certain power loss, more mechanical devices increase the possibility of wear and failure. However, DC motor has many disadvantages, such as excessive noise, brush ignition, rotor pollution, too high motor temperature, insufficient exhaust and motor vibration. Therefore, the maintenance cost of screw extruder with DC motor is higher, and the initial cost of DC motor is higher.
After the transformation, Tianlang Weichuang vl6100 series inverter has the following characteristics
1) There are multiple input signal channels, which can accept analog signals from sensor voltage, current, pulse, etc. And multi segment speed, forward and reverse jog and 485 communication directly set frequency.
The main process requirement of extruder is to control the constant pressure at the outlet. When the equipment starts to work, the rotating speed is controlled manually, and when the required pressure is reached, the pressure control is switched immediately.
2) The main drive motor of the Extruder mainly drives the screw to rotate after decelerating by the parallel axis helical gear reducer. When the running speed is changed below the fundamental frequency, it is a constant torque speed regulation.
Vl6100 series frequency converter has the function of automatic energy saving control, which can automatically adjust the voltage according to the load condition, so that the motor can run in high efficiency state.
3) Torque limit and slip compensation torque limit and slip compensation function make the output torque constant, torque ripple small, meet the product process requirements.
The vl6100 series frequency converter of Tianlang Weichuang is used in the precision extruder, which not only saves electric energy, but also improves the process, product quality and competitiveness.
