Lesson 9 - Clarification – Filtration SAQ
This lesson allows you to test yourself on the material covered in the Clarification – Filtration lesson, and determine the level to which you have met the learning outcomes.
Suggested Response - Q2
**Answer BOTH parts of this question:
a) Filtration is the separation of solids via which three mechanisms?
b) Explain the function of one of these filtration mechanisms and what filter technologies deliver this?
Response:
a) Depth filtration, surface filtration and adsorption.
b) Depth filtration is when the septum is pre-coated with a filter aid in advance of the beer filtration run; it forms the base layer for the filter bed. The course filter powder is dosed on first as the finer filter powders would pass straight through the holes in the filter plates. Matured beer is dosed with filter aid continuously (called body feed), at a concentration that is based on the solids content to be removed; this maintains a good filter bed permeability. During the filter run, the bed increases in thickness due to the body feed building-up in concentration on the filter plates.
The filter technologies available for this include plate and frame, sheet filter, horizontal leaf, and candle filters.