Which type of centrifuge utilizes a knife or plow to remove the "cake"?

The type of centrifuge that utilizes a knife or plow to remove the "cake" is indeed the basket centrifuge. This type of centrifuge is designed specifically for solid-liquid separation, where the solid material builds up as a cake along the wall of the basket during the centrifugal process.

In a basket centrifuge, the rotating basket creates centrifugal force that separates the solids from the liquid. As the solids collect and form a cake, the knife or plow can be employed to scrape the solids off the basket wall efficiently. This scraping mechanism is crucial for ensuring that the cake can be removed without disrupting the operation or leaving excessive residue, which is particularly important for effective cleaning and operational efficiency.

Understanding this mechanism is critical for wastewater operators, as it helps them decide which type of centrifuge is best suited for various applications in the treatment process. While the other options, such as the disc, scroll, and decanter centrifuges, serve different operational functions and employ varying methodologies for solids removal, they do not utilize a knife or plow mechanism specifically designed for this task like the basket centrifuge does.