Whether drying equipment requires a vacuum pump depends on the drying process, material properties, and equipment type. Some dryers operate at atmospheric pressure, while others require a vacuum system to achieve the required drying conditions.
Drying equipment that does not require a vacuum pump
These dryers operate at atmospheric pressure and remove moisture through hot air circulation, contact heat transfer, or radiant heating. They do not require a vacuum pump to maintain negative pressure.
Common examples include:
Hot air circulation drying ovens
These ovens use a fan to circulate heated air through the drying chamber and carry moisture away from the materials. The drying process takes place at atmospheric pressure without requiring a vacuum system.
Multi-layer belt dryers
Multi-layer belt dryers convey materials through the drying equipment on a series of belts. Hot air passes through the material, or radiant heating is used to supply heat. Drying takes place under atmospheric pressure.
Drum scraper dryers
These dryers spread material over the surface of a heated drum. Heat transfers directly from the drum to the material, removing moisture without requiring a vacuum environment.
Atmospheric fluidized bed dryers
Atmospheric fluidized bed dryers use heated airflow to suspend and move particles during drying. The airflow promotes heat and mass transfer, allowing the materials to dry under atmospheric pressure.
Drying equipment that requires a vacuum pump
Vacuum drying equipment uses a vacuum pump to remove air from the chamber and maintain reduced pressure. This allows drying to take place under conditions that may be unsuitable for conventional atmospheric drying.
Vacuum dryers
Common types include double-cone rotary vacuum dryers, rake vacuum dryers, and laboratory vacuum drying ovens.
By reducing the pressure inside the chamber, these dryers allow moisture to boil and evaporate at lower temperatures. They are suitable for heat-sensitive or oxidation-prone materials. Some processes can also recover organic solvents released during drying.
Freeze dryers
Freeze dryers operate by freezing the material at low temperatures and then reducing the pressure to support sublimation. The water in the frozen material changes directly from solid ice to vapor, which is removed from the drying system.
Freeze drying is commonly used for high-precision drying applications in biopharmaceutical production and premium food processing.
Vacuum spray dryers
Vacuum spray dryers atomize the feed material and dry the resulting droplets inside a chamber maintained at reduced pressure. A vacuum pump maintains the required pressure conditions, supporting drying efficiency and helping protect heat-sensitive materials.
Drying equipment that can optionally use a vacuum pump
Some drying equipment designed for atmospheric operation can be modified to support vacuum drying. For example, certain hot air circulation ovens can be fitted with a vacuum connection and a compatible vacuum pump to enable low-temperature vacuum drying for heat-sensitive materials.
This modification depends on the equipment design and pressure requirements. A vacuum connection and pump are optional additions rather than standard features of conventional hot air circulation ovens.
Custom machining for industrial equipment
In addition to components used in drying equipment, Hansheng Automation provides custom precision machining for non-standard industrial parts based on customer-provided drawings. Our services also cover components for filling machinery, tobacco packaging equipment, yacht systems, and remote control racing cars. Each part is manufactured according to the specified dimensions, structural requirements, and drawing details.
