Question

The drier that can be used for carrying out the instantizing or agglomeration process is:

• A. Drum drier
• B. Spray drier
• C. Tunnel drier
• D. Kiln drier

Hint:

Associate "instant" powders with agglomeration. The best way to create these porous, easy-to-dissolve granules from a liquid feed is by using a sophisticated spray drying process.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Instantizing is a process that improves the dispersibility and solubility of a dried powder in a liquid (e.g., instant coffee, instant milk powder). This is achieved through agglomeration, where fine powder particles are clustered together to form larger, porous granules. These granules sink into the liquid and wet more easily than fine powders.
Step 3: Detailed Explanation:
- A Spray drier is uniquely suited for this process. In modern multi-stage spray driers, the initial drying creates fine particles. These fine particles are then passed through a zone of high humidity (often by reintroducing steam or fine water mist) near the bottom of the drier. This makes their surfaces sticky.
- They then enter a secondary drying stage, typically an integrated fluid-bed drier, where the sticky particles collide and bind together, forming larger agglomerates. This two-step process within a single system is the standard method for instantizing.
- Drum driers, Tunnel driers, and Kiln driers are not designed for this process. They produce flakes, large dried pieces, or bulk dried materials, and they lack the mechanism for controlled re-wetting and agglomeration of fine particles.
Step 4: Final Answer:
The spray drier, particularly a multi-stage system with a fluid bed, is the equipment used for the agglomeration and instantizing process. Therefore, option (B) is correct.