Structure and principle of pneumatic vacuum feeder:
1、 Core structure
1. Power plant
Pneumatic vacuum pump: a multi-stage jet vacuum pump or vacuum generator driven by compressed air to generate a negative pressure environment; Some equipment uses motor-driven vacuum pumps, but pneumatic ones do not require lubricating oil or mechanical moving parts, resulting in lower maintenance costs.
Compressed air system: provides the power source required for pneumatic vacuum pumps and participates in the blowback cleaning process.
2. Filtering system
Filter: located between the silo and the vacuum pump, used to separate materials from air and prevent particles from entering the vacuum pump or polluting the environment.
• Backblowing air path: Start during the unloading stage, backwash the filter with high-pressure gas to remove attached particles and maintain filtration efficiency.
3. Material conveying components
• Storage bin: Temporarily storing the inhaled material, usually equipped with a level gauge or delay relay to control the amount of material absorbed.
• Suction tube/conveying pipeline: Connect the suction port to the silo, and transport powdered or granular materials under negative pressure environment.
• Storage bin door: It opens during unloading and allows materials to fall freely through air pressure balance.
4. Control system
• Timing control module: Control the suction time, discharge interval, and blowback cycle through knobs, delay relays, or PLC.
2、 Working principle
1. Negative pressure suction stage
After starting, the compressed air drives the vacuum pump to generate negative pressure, creating a vacuum environment inside the silo. The external atmospheric pressure sucks the material into the silo through the suction tube.
The filter synchronously blocks material particles, and clean air is discharged through a vacuum pump.
2. Unloading and Air Pressure Balance
After the suction amount reaches the preset value (controlled by the level gauge or time), the vacuum pump stops, the bin door opens, and the material falls to downstream equipment due to gravity.
During unloading, the internal and external air pressure of the system is restored to balance, ensuring smooth discharge of materials.
3. Backblowing cleaning stage
During the unloading process, activate the reverse air flow path, and high-pressure gas will reverse flush the filter to remove attached particles and prevent blockage.
4. Circular homework
After unloading is completed, the bin door closes, the vacuum pump restarts, and enters the next suction cycle, cycling until the stop command is triggered.