Lamella plates work by

Lamella plates work by

• A. using plates inclined by 40 degrees
• B. first using plates inclined downward by 20 degrees and then upward into plates inclined by 45 degrees
• C. using plates directed downward at 45 degrees then upward at 45 degrees
• D. using parallel plates that direct the water downward then upward at 55 degrees

Answer: (B)

Lamella plates boost settling by providing a large surface area on inclined surfaces, so particles can settle onto the plates while the liquid moves slowly along them. The arrangement with plates first inclined downward by a small angle and then upward into plates inclined by 45 degrees creates a gentle, serpentine flow path. Water enters and travels downward along the initial set, giving solids a chance to settle onto the plate surfaces and slide toward the sludge collection area. The following upward section directs flow through additional plates, increasing contact time and helping keep settled sludge from being disturbed, which improves removal efficiency. This two-stage path maximizes settling area and retention time more effectively than a single incline or a simple parallel-plate setup.

Lamella plates boost settling by providing a large surface area on inclined surfaces, so particles can settle onto the plates while the liquid moves slowly along them. The arrangement with plates first inclined downward by a small angle and then upward into plates inclined by 45 degrees creates a gentle, serpentine flow path. Water enters and travels downward along the initial set, giving solids a chance to settle onto the plate surfaces and slide toward the sludge collection area. The following upward section directs flow through additional plates, increasing contact time and helping keep settled sludge from being disturbed, which improves removal efficiency. This two-stage path maximizes settling area and retention time more effectively than a single incline or a simple parallel-plate setup.