Filter types: which of the following is a continuous filter for large-scale operations?
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APlate and frame filter
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BCartridge filter
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CShell and leaf filter
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DNone of these
Answer
Correct Answer: None of these
Explanation
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