Question

The more appropriate purpose of spiral scrapper in Swenson-Walker crystalliser is:

• A. Agitation of sample (solution)
• B. Conveying the crystals
• C. Prevent an accumulation of crystals on the coolingsur face
• D. Provides desired temperature to the sample (solution)

Answer 1

The Correct Option is A

To determine the appropriate purpose of the spiral scraper in a Swenson-Walker crystallizer, let's explore the functions of such crystallizers and their components.

A Swenson-Walker crystallizer is typically used in the crystallization process in the chemical industry. This type of crystallizer is classified as a cooling crystallizer and has a long trough with a cooling surface along which the solution flows.

The spiral scraper is an important part of this equipment, designed to perform specific functions:

1. Agitation of sample (solution): The spiral scraper aids in mildly agitating the solution. This promotes uniform cooling and prevents concentration gradients, which can lead to uneven crystal growth. Agitation is essential for efficient crystallization.
2. Conveying the crystals: While movement of crystals is a secondary action, it helps to some extent in conveying crystals along the trough; however, this is not its primary function.
3. Prevent an accumulation of crystals on the cooling surface: The motion of the spiral scraper can help keep the cooling surface clean to a degree, but this is not the main design purpose.
4. Provides desired temperature to the sample (solution): The scraper does not regulate the temperature; it is the cooling/heating mechanism's attribute in the crystallizer.

From the above points, it's clear that the primary purpose of the spiral scraper in a Swenson-Walker crystallizer is to agitate the sample (solution). This option is correct, as agitation is pivotal for the process to ensure uniform crystal formation and avert the settlement of particles.

Thus, the correct answer is: Agitation of sample (solution).