There are significant differences between vacuum dryers and ordinary dryers in terms of working principles, application scenarios, and drying effects. The following is a detailed comparison of the two:
1. Working principle
Comparison items: vacuum dryer, ordinary dryer
The ambient pressure is to operate in a vacuum environment (with pressure lower than atmospheric pressure) or under normal or high pressure conditions
Water evaporation: Water evaporates at low temperatures (boiling point decreases). Water evaporates at high temperatures (boiling point remains normal).
The heating methods usually adopt heat conduction, radiation or microwave heating, mainly through hot air convection or conduction heating
2. Drying effect
Comparison items: vacuum dryer, ordinary dryer
Low-temperature drying is controlled to prevent damage to materials by high temperatures. A higher temperature is required, which may damage heat-sensitive materials
Oxidation risk: Isolate oxygen in a vacuum environment to prevent oxidation. Oxidation reactions are prone to occur under normal pressure
At low temperatures, water evaporates quickly, and the drying time may be shorter. At high temperatures, the drying speed is faster, but the energy consumption may be higher
The material form is suitable for fragile, easily deformable and heat-sensitive materials, as well as for high-temperature resistant and non-oxidizable materials
3. Application scenarios
Comparison items: vacuum dryer, ordinary dryer
Drying heat-sensitive foods (such as coffee, milk powder, and Chinese medicinal materials) and high-temperature resistant foods (such as grains and nuts) in the food industry
Drying of non-heat-sensitive drug raw materials such as medicines, biological products and vaccines in the pharmaceutical industry
The chemical industry dries chemical raw materials that are prone to oxidation and decomposition, as well as high-temperature resistant chemical products
Drying of electronic components and semiconductor materials in the electronics industry, as well as non-precision electronic components
Drying of conventional materials such as nanomaterials and polymer materials in the new materials industry
4. Comparison of advantages and disadvantages
Vacuum dryer
Advantages
Low-temperature drying protects heat-sensitive materials.
Isolate oxygen to prevent oxidation.
Fast drying speed and low energy consumption.
Disadvantage
The equipment cost is high.
The maintenance of vacuum systems is complex.
The drying capacity is relatively small.
Ordinary dryer
Advantages
The equipment cost is low.
Large drying capacity.
Simple to operate and convenient to maintain.
Disadvantage
High temperatures may damage the composition of materials.
It is prone to oxidation reactions.
The energy consumption is relatively high.
5. Applicable material examples
Materials suitable for vacuum dryers
Coffee beans (retain flavor at low temperature)
Chinese medicinal materials (avoid high temperatures that may damage their efficacy)
Biological products (such as vaccines, enzyme preparations
Electronic components (to prevent oxidation
Materials suitable for ordinary dryers:
Grains (such as rice and wheat
Nuts (such as peanuts, almonds
High-temperature resistant chemical raw materials (such as ammonium sulfate)
Non-precision electronic components (such as resistors and capacitors
Choosing a vacuum dryer: When the material is heat-sensitive, prone to oxidation or requires low-temperature drying, a vacuum dryer is a better choice.
Choose a common dryer: When the material is resistant to high temperatures, not prone to oxidation and requires large-capacity drying, a common dryer is more cost-effective.
Selecting the appropriate drying equipment based on specific requirements and material characteristics can enhance production efficiency and product quality.