Question

The appearance, size, shape, density, and solubility of the final spray dried particle can be affected by % List

[A.] Nozzle pressure
[B.] Liquid viscosity
[C.] Surface tension
[D.] Nature of the solids
Choose the most appropriate answer from the options given below:

• A. A, B, and D only
• B. A, B, and C only
• C. A, B, C, and D
• D. B, C, and D only

Hint:

In spray drying, everything matters. The process variables (\textbf{nozzle pressure}), the feed properties (\textbf{viscosity, surface tension}), and the composition (\textbf{nature of solids}) all interact to determine the final powder's characteristics.

Answer 1

The Correct Option is C

Step 1: Analyze how each factor influences the spray drying process.
A. Nozzle pressure: Directly affects the energy of atomization, which in turn controls the initial droplet size. Smaller droplets dry faster and result in smaller final particles.
B. Liquid viscosity & C. Surface tension: These are properties of the liquid feed that resist atomization. Higher viscosity and surface tension make it harder to form small droplets, leading to larger final particles.
D. Nature of the solids: The type of solid (e.g., crystalline vs. amorphous), its concentration, and its properties affect how the particle forms as it dries. It influences the final particle's density, shape (e.g., hollow or solid), and solubility. Since all four factors have a significant impact on the final particle characteristics, the correct answer includes all of them.