automatic plastic powder gravimetric dosing conveying system
The PVC materials compounding system is the former part of the PVC production line, which is one of the key to the long-term stable production of the whole line.The automation degree of the compounding system determines the automation degree of the whole production line.
Automatic PVC compounding system is usually composed of the following subsystems: material collection system, material conveying system, metering batching system, mixing unit, material storage equipment,
feeding system, dust removal system: central control system, central monitoring system ,etc.The composition and principles of the subsystems are described as below:
1. Material collection system
The material collection system is used to collect bulk or bagged raw materials into storage silos in various ways.
Bulk materials can be sent directly to the storage tank through the pneumatic conveying device on the tanker, and the bag materials is collected by the bag opening station.
2. Material conveying system
The conveying of the materials is the key to the automation of the compounding and feeding system. In the PVC automatic compounding system, the conveying system occupies a large proportion:Including the conveying from the bagging station to the transition silo upon the batching scales,the finished materials conveying from the mixer to the finished silo ,and also the finished materials conveying from the finished silo to the extruder.
3. Weighing batching system
In the PVC automatic compounding system, the weighing batching system is normally composed of two separate subsystems: a set of main materials weighing batching system and a set of auxiliary materials weighing batching system. Each batching system has the feeding silo for each material,also with the screw conveyor,batching sales and etc.
4. Mixer Unit
The high speed hot and cooling mixer is a preferred equipment suitable for the PVC blending process, which is a combination of a high speed hot mixer and a horizontal cooling mixer. The high speed hot mixer has three mixing blades and diversion section etc.Under its action, materials will rotate ,flip and other complex movement with high speed,so that the temperature will rise rapidly to meet the requirements of the material mixing process.Then materials enter the horizontal cooling mixer,it will cool down quickly to meet the production process requirement by low-speed mixing blade movement and heat exchange with the water cooling system.
5. Material storage equipment
Material storage equipment are separately silos mainly used for storing raw materials and finished materials.
PVC raw material storage silo has 150m3 of effective volume.The material touching storage materials are all stainless steel,and polished . The outside surface is done with pickling passivation treatment.Consist with silos,dust removal equipment upon the silos ,steel ladder,fences,
decompression cap,gate,and other components etc.
Can automatically control the materials incoming and outgoing by setting the level gauge, it has nice appearance,strong structure,wind proof and other features.
In order to ensure the qualified rate of the finished tubes, it is necessary to consider the surplus volume of the finished material's silos, normally not less than 12 hours, and also the finished material silos' design adopts the homogenized structure to ensure that the materials are not separated from the stratification.
6. Dust removal system
The model of the dust collector is varies depending on the case of use.We use the imported coating materials as the filter material in dust collector,the filter aperture's size should less than 0.5 microns, which is the most advanced filter material in the world.
The service life can be extended to more than 10 years and don't need to change if choose the sintered filter.
7. Electrical Control System
The electrical control system connects the complete set of equipment together.It is the guarantee of long-term stable operation of the compound mixing line.We designs the electronic control system including the on-site operation cabinet and the central control system, and can realize the following functions:
Automatic detection functions:
Control functions (the entire system achieve three-level control):
Automatic alarm,Interlock functions:
8. Auxiliary equipment:
The auxiliary equipment includes an operating platform, sieves,rotor splitters, switching valves,pipes and etc.
9. Feeding system for extruder
Feeding system is composed of vacuum feeder or spring feeder.
Vacuum feeder composed of the feeding funnel, suction gun,vortex fan, pulse filter,butterfly valve and storage silos. The biggest rated feeding capacity is more than 1500kg / h.
Spring feeder is a rodless screw conveyor,can be bend in a certain degree, suitable for the feeding for the extruder.
In summary, we design a specific program for the PVC automatic compound feeding system based on different conditions and different investment quotas.