Automatic PVC compounding system is usually composed of the following subsystems: material collection system, material handling system, metering batching system, mixing unit, material storage system, extruder feeding system, dust removal system: central control system, central monitoring system Wait.
The composition and principles of the subsystems are described 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 material can be sent directly to the storage tank through the pneumatic conveying device on the tanker, and the bag material is collected by the bag opening station.
Bags the box material and material contact materials are 1Cr18Ni9Ti stainless steel. The inner surface of the polished. Sealed structure. Open the bag points automatically open the bag and artificial open two bags:
The artificial door is made of protective door, vibrating screen, magnetic frame, broken arch, etc. The protection door is divided into two layers inside and outside, and the outer layer is stainless steel door, which can be opened and closed. The vibrating screen can effectively filter out impurities that are mixed in the powder, such as sewing thread, shredding sheet, large particles, etc., the magnetic frame can be initially removed from the material. Iron impurities, broken arch device by the cylinder and broken arch composition. Contributed to the smooth flow of materials.
The bag is made of a conveyor, a bag, a filter, a collector, a drain, etc. The bag is fed into the bag by means of a conveyor, and a helical reamer is provided in the bag. The bag is sent to the filter along with the material, and the filter separates the material and the bag, and the material enters the collector.
2. Material handling system
The transportation of the material is the key to the automation of the compound production line. In the PVC automatic compound system, the conveying system occupies a large proportion: the raw material is transported from the bagging station to the above batching material. The conveyance of the finished material from the finished silo to the extruder.
There are two main forms of application here: spiral conveying and pneumatic conveying, while the pneumatic conveying can be based on the actual use of dilute phase positive pressure. Dense phase negative pressure.
The screw conveyor consists of a motor, a reducer, a screw body, a simple structure, a reliable operation, but a higher cost when the transport distance is longer.
The core part of the dense phase pneumatic conveying system is a storage type pneumatic pump (referred to as the tank pump).
The pump is supplied by the tank, the butterfly valve, the exhaust valve, the feed port, the gas pipeline, etc. The main equipment in the dense pneumatic conveying system.When the compressed air enters the inlet valve of the transmitter, The inside of the cone is raised and the vortex is generated by the gas.With the increase of the internal pressure of the transmitter, the material is fed into a vortex flow to achieve the purpose of smooth transportation of the material. Low air pressure can be used to achieve low speed Concentration of delivery.
The system has the advantages of low noise, long transport distance, low energy consumption, low throughput of large pipeline and low working pressure (0.15 ~ 0.3MPa), so it will not form clogging in the pipeline, In the pipeline at a certain distance to increase a set of booster device so that the material in the pipeline was plug-like (that is, a section of the interval between the air column and material column) forward movement, it is impossible to material separation layering. Suitable for the transport of the mixture. The use of the booster device can also effectively reduce the material forward speed.
Diluted positive pressure pneumatic conveying equipment generally by the Roots blower. Rotary feeder. Venturi generator.
The Roots blower is responsible for providing the low pressure air required for conveying the material. To ensure the stability of the air pressure, the upper part of the rooftop fan is equipped with a certain volume of air bag. The rotary feeder is a quantitative feeding device. Since the rotary feeder is used in conjunction with the Roots blower, it is advisable to prevent the air from leaking into the silo, which is similar to that of a tee. The venturi is shaped like a tee. The air flow pipe is designed for the use of the Venturi principle. The air flow resistance is small and the airflow diverges less.
The biggest advantage of the dilute-phase pneumatic positive pressure transmission is that it does not require a special compressed air supply, but the noise is higher, the conveying distance is short, and the separation layer of the material is easy to be formed during the transportation process.
The dilute-phase pneumatic negative pressure transmission mainly uses the vortex fan to produce the vacuum absorbing material, and then separates the material from the gas through the dust filter device.
The advantages and disadvantages of the negative pressure transmission is similar to that of the dilute phase, but it is not easy to cause clogging.
3. Weighing the ingredients unit
In the PVC automatic compound system, the weighing batching system is normally composed of two separate subsystems, a set of main ingredient weighing system and a set of batch weighing system. Each set of ingredients is made of the material The corresponding screw conveyor. Parts of the scale and other components.
The weight scale of the main weighing scale is large, and it is suitable for weighing the high proportion of the material, and the rated scale of the auxiliary scale is small, which is suitable for weighing less material.
The silo is to be designed according to the different materials, including the warehouse top dust collector, the warehouse wall is equipped with high and low level meter.Long flow of material out of the material with a tapered natural blanking.When the poor mobility can increase in the outer wall of the electric Or pneumatic chamber wall vibrator, or install a gas flow pad or a special material coating on the inner wall to facilitate smooth flow of material. For particularly easy-to-bond materials, the silo can be designed to be flat.
The main form of the main material feeder is the feeding of the screw conveyor, and the spiral blade is designed for variable pitch, ensuring the uniform feeding, and adjusting the feeding speed through the inverter.
The material is sealed by the sealed box into the weighing unit, and when the weighing unit sends a signal to a predetermined value, the material gate is driven by the cylinder. Of the air material column.
This structure allows the air material column to fall into the weighing unit to reduce the material. Easy to control the measurement accuracy. Similarly, the screw machine is also easy to repair. Open the relevant maintenance hole. The operation of the various parts is very clear. Set the shaft seal away from solid materials It is also possible to effectively prevent the solid material from pressing on the seal and improve the reliability of the use. In addition, it is only necessary to unscrew a few pieces of bolts to clean up. The
Screw conveyor due to the different materials. Set a single double screw feeding two different feeding type.
The double helix feed unit consists of a large, two, two-screw machine, which is operated by a large, small screw machine at the beginning of the feed, and when the feed reaches 90% of the rated value, the large screw machine is stopped and the small screw machine continues to work. The feeder can increase the weighing speed and improve the weighing accuracy, and it is suitable for the smaller material.
4. Mixing equipment
High cold mix unit is suitable for PVC mixing process of the preferred equipment. Domestic high. Cold mixing unit although the technology has been mature production has also been serialized. And many domestic PVC manufacturers have a lot of applications, but the failure rate is high. So the company in the program using Taiwan's overseas product company. High cold mixing unit is a high-speed mixer and a horizontal cooling mixer combination. High-speed mixer with three mixing pulp and baffle Etc. The material is under its action, such as high-speed rotation and flip and other complex movement, so that the temperature rises rapidly to meet the requirements of the material mixing process.Then enter the horizontal cooling mixer through the mixing of low-speed operation of the slurry and the water cooling system heat exchange. So that the material quickly cooled to meet the production process requirements.
5. Material storage device
Material storage equipment mainly refers to the raw materials and finished materials stored in the various silos.
PVC raw material storage silo effective volume design for the 150m3. Material contact with the material are 1Cr18Ni9Ti stainless steel. Surface polishing. Surface pickling passivation treatment. By the warehouse. Covered dust collector. Steel ladder. Fence. Decompression Cap, gate and other components, etc., through the set of high and low level meter can be automatically controlled into the material and a beautiful appearance. Strong structure. Wind and other characteristics.
6. 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 the precipitator should be imported into the coating material.The filter aperture is less than 0.5 micron, which is the most advanced filter material in the world.
If you use sintered filter filter can make the service life extended to more than a decade without the need to replace.
7. Electrical System
The electrical control system connects the complete set of equipment together.It is the guarantee of long-term stable operation of the mixing line.The company designs the electronic control system including the on-site operation cabinet and the central control system, and can realize the following functions.
Automatic detection function:
● Automatically detect the operation of all motors in the production process,
● automatic detection of various types of production process switch. Valve switch in place,
● automatic detection of the production process of the packaging scale. Ingredients weight information,
● Automatic detection of production process shows. Record. Accumulation of production situation.
Control function (the entire system to achieve three levels of control):
● individual live switch button hard hand operation,
● control room manual operation,
● PLC automatic control and PC keyboard and mouse control on the screen.If the computer fails, you must ensure that the PLC to maintain a period of production until the computer troubleshooting.
Automatic alarm. Interlock function
● Motor abnormal status alarm
● Valve position alarm
● Technical parameters on the lower limit alarm. If the material level. Weight. Pressure and so on
● Punching and interlocking control of various valve positions
● High-cold mixer interlock control and other important equipment classification alarm
● Check the equipment failure. Indicator. Alarm
● All Chinese visual human-computer interface
● Process flow chart. Total screen and sub-screen display
● Control parameter trend graph
● Operational guidance
● Automatic production control curve
● Automatic collection and preservation of data and classification management. Automatic statistical processing of data
● Historical data management. Can print the class report. Daily report. Monthly report and annual report. And to the senior leadership of the bar chart.
● Automatic printing
● security. Confidential group management
● Open architecture. Extensible. Can be remotely networked
The central control system is equipped with configuration software development. All Chinese interface. Suitable for China's national conditions.
I plant the integrity, strength and quality of products recognized by the industry. Welcome friends from all walks of life come to visit our factory, guidance and business negotiations.