Question

Which of the following DRYERS is a "static bed dryer"?

• A. Freeze dryer
• B. Fluid bed dryer
• C. Spray dryer
• D. Flash dryer

Answer 1

The Correct Option is A

To determine which of the given dryers is a "static bed dryer," let's first understand what a static bed dryer is.

A static bed dryer is a type of drying equipment where the material to be dried is placed in a stationary container, and the drying is achieved by blowing air through the bed of material. The key characteristic of a static bed dryer is that the material remains stationary while the drying process takes place.

Now, let's analyze each option:

1. Freeze Dryer: A freeze dryer, also known as a lyophilizer, involves freezing the material and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase. It is a form of static drying as the material is stationary during the process. Thus, a freeze dryer is considered a static bed dryer.
2. Fluid Bed Dryer: This dryer uses fluidization to dry the material, meaning it creates a moving bed of material by blowing air through it, which causes the particles to float. This is not a static bed but a dynamic process.
3. Spray Dryer: A spray dryer involves atomizing the liquid into a spray of droplets and then drying it rapidly by contact with hot air. This involves dispersing material in air and is not static.
4. Flash Dryer: A flash dryer works by pneumatic drying where solids are conveyed in a hot air stream. Similar to a spray dryer, it involves material movement during drying.

From the analysis above, the correct answer is the Freeze Dryer as it involves drying with the material kept stationary in a chamber, fitting the description of a static bed dryer.