In paper manufacturing, filtration of large volumes of process water is commonly carried out using which type of filter arrangement?

Introduction / Context:
Paper mills require substantial quantities of clarified water. The filtration stage must be simple, robust, and capable of continuous operation at large throughputs.

Given Data / Assumptions:

• Goal: clarify process water (low solids loading).
• Industrial scale, continuous operation preferred.
• Economical and easily maintained equipment is ideal.

Concept / Approach:
Open (rapid) sand filters are widely used for water clarification in utilities and process plants. They remove suspended fines with low head losses and are easily backwashed. Plate-and-frame presses, vacuum leaf, or sparkler filters are more suitable for slurries with higher solids content and batch or semi-batch operation, not for primary water clarification at such volumes.

Step-by-Step Solution:
Identify water clarity requirement vs. slurry dewatering.Select high-throughput, continuous filtration with easy backwash.Choose open sand filtration.

Verification / Alternative check:
Utility water treatment in mills often uses coagulation–flocculation followed by rapid sand filtration, aligning with this selection.

Why Other Options Are Wrong:
Filter press/leaf filters: suited to higher solids slurries, typically batch.Candle microfilter: excessive for general process water volumes, higher cost.

Common Pitfalls:
Confusing process water clarification with product slurry dewatering steps.

Final Answer:
Open sand filter