PVC/SPC Automatic Dosing System Description:
PVC mixing system is the front part of PVC production line. It is the key for the production line to achieve long-term stable production. The automation degree of mixing determines the automation degree of the whole production line. Automatic PVC dosing system is usually composed of the following subsystems: material collection system, material conveying system, weighting and batching system, mixing unit, material storage system, extruder feeding system, dust removal system, central control system, central monitoring system, etc.
Composition and Principle of Subsystems:
1. Material Collection System
Material collection system is used to collect bulk or bagged raw materials into storage bin in various ways. Bulk materials can be sent directly to the storage bin through the pneumatic conveying device on the tank car, and the bag materials can be collected by the open bag station.
2. Material Conveying System
Material transportation is the key to realize automation of mixing production line, occupies a large proportion in the PVC automatic mixing system, includes the transportation of raw materials from the bag opening station to the excessive silo above the batching scale, delivery of finished materials from mixer to finished silo, delivery of finished material from finished material bin to extruder.
The system has the advantages of low noise, long transportation distance, low energy consumption, large transportation capacity, low pipeline wear and so on, and because of its high working pressure, material will not form blockage in the pipeline.
3. Weighting and Batching System
In PVC automatic dosing system, the weighing and batching system is normally composed of two independent subsystems: a set of main material weighing and batching system and a set of auxiliary material weighing and batching system. Each batching system is made up of the feeding bin of each material, corresponding screw conveyor, ingredients scale, etc. The rated scale of the main material scale is large, so it is suitable for weighing high proportion main material. The rated scale of the auxiliary material scale is small, so it is suitable for weighing less material. This design helps to improve the accuracy of ingredients.
4. Mixing Unit
The mixing unit is composed of a high-speed mixer and a horizontal cooling mixer. The high speed mixer is equipped with three mixing blades and guide plates. Under its action, the material makes complex motion such as high speed rotation and turning, which makes the temperature rise rapidly, meets the requirements of the material mixing process, and then enters the horizontal cooling mixer. Through the heat exchange between the low speed operation of the mixing slurry leaf and the water cooling system, the material can be cooled quickly to meet the requirements of the production process.
5. Material Storage System
Material storage equipment mainly refers to the storage of raw materials and finished materials. In order to ensure the qualified rate of the product, the volume of the finished product bin should be considered to have a certain amount of wealth, generally not less than 12 hours.
6. Extruder Feeding System
The feeding system of extruder is composed of vacuum feeder or screw feeder.
7. Dust Removal System
According to the use of different occasions, the type of dust collector is different. It is suggested that the filter material of dust collector should be imported coating material, the aperture of the filter element is less than 0.5, and the inlet peritoneal filtration material should be used. If the sintered filter is selected, the service life can be extended to more than 10 years without replacement.
8. Electrical System
The electrical control system connects the whole set of equipment together. It is the guarantee of long-term stable operation of mixing line. The electronic control system designed by our company includes field operation cabinet and central control system. It can achieve the following functions.
● Automatic detection function
● Control function (the whole system realizes three levels of control)
● Automatic alarm and interlock function
● Self-diagnostic function
● Management function
