Filter types: which of the following is a continuous filter for large-scale operations?

Introduction / Context:
Filtration equipment can be broadly classed as batch or continuous. Recognising which devices are inherently batch helps select the right hardware for steady, high-throughput duty.

Given Data / Assumptions:

• Options limited to plate and frame, cartridge, and shell-and-leaf filters.
• “Continuous filter” refers to machines like rotary drum, rotary disc, or continuous vacuum belt filters operating without cycle interruptions.

Concept / Approach:
Plate-and-frame and cartridge filters are classical batch units: they must be stopped to discharge cake or replace elements. Leaf filters (shell-and-leaf) are also typically operated batchwise with cycles of filtration, cake washing, drying, and blowback discharge.

Step-by-Step Solution:
Identify each option as batch-operated.Conclude that none of the listed units is continuous in the strict sense.Therefore select “None of these.”

Verification / Alternative check:
Continuous filters prominently include rotary drum vacuum filters, rotary disc filters, and continuous belt filters—none appears among the options.

Why Other Options Are Wrong:
Plate-and-frame: batch by design.Cartridge: element replacement requires shutdown → batch.Shell-and-leaf: commonly batch cycles; not continuous discharge.

Common Pitfalls:
Assuming “leaf” implies continuous because of multiple leaves; despite large area, operation is cyclic.

Final Answer:
None of these