Working Principle of Square-Type Vacuum Drying Equipment

Working Principle of Square-Type Vacuum Drying Equipment

Square-type vacuum drying equipment is a type of static vacuum drying equipment. Its working principle is based on “vacuum lowering the boiling point + conduction heating + moisture extraction and recovery.”

1. Sealed chamber evacuation: The sealed square chamber is evacuated by a vacuum pump to create a negative-pressure environment.
2. Vacuum lowers boiling point: Under negative pressure, the boiling point of water drops sharply, allowing vaporization at low temperature.
3. Boiling point varies with vacuum: The higher the vacuum degree, the lower the boiling point, and the milder the drying temperature.
4. Conduction heating is primary: Heat is mainly conducted through shelves or racks and supplied directly to the material.
5. Heating medium circulation: Hot water, steam, or thermal oil flows through the shelves for continuous and stable heat transfer.
6. Trays carry the material: The material is spread flat on drying trays and kept static; heat passes through the tray bottom into the material layer.
7. Surface moisture vaporizes: Surface moisture in the material layer absorbs heat and vaporizes into the vapor space inside the chamber.
8. Internal moisture migrates outward: Internal moisture permeates toward the surface, and the surface continues to vaporize.
9. Vacuum pump extracts moisture: The vacuum pump continuously removes water vapor to maintain a low moisture partial pressure.
10. Condenser recovers solvent: Condensable solvent vapor is condensed and liquefied for recovery, reducing emissions.
11. Static drying preserves shape: The material remains static without turning throughout the process, so granular or flake forms are not damaged.
12. Multi-point evacuation improves uniformity: The chamber is evacuated at multiple points, so the evacuation rate and temperature at each point tend to be uniform.