Identify the constraint before selecting samples
Describe the sludge and conditioning, then state whether initial drainage, filtrate, capture or cake release limits the belt press. Record the current code and operating conditions. A generic request for strong cationic polymer can miss the actual failure mode.
Ask why the proposed candidates belong in the screening set. Charge description and molecular profile are variables to assess, not an automatic ranking from weakest to strongest.
Keep preparation and machine effects visible
Prepare each code under its confirmed instructions and verify consistent stock delivery. Compare drainage with the relevant liquid and solids outcomes. A bench observation can support selection for equipment work but cannot establish the final press result by itself.
During a bounded press comparison, retain feed conditions and relevant settings. If cloth condition or operating adjustment changes, record it explicitly. Do not credit a polymer for an unrelated improvement in equipment operation or reject it for an uninvestigated delivery problem.
Order against the accepted operating window
Retain the selected sample, preparation demand and measured consumption. State which feed variation was represented and which remains untested. A narrow favorable run may justify a restricted first delivery rather than unrestricted routine approval.
Review cationic supply identity with the handover record. Request packaging and documents for the actual order. If a new supplied form is proposed, use the preparation-fit comparison before assuming it can replace the approved product directly.
Keep these purchase records
| Decision | Evidence to retain |
|---|---|
| Required result | Drainage, filtrate and cake release requirements are defined before ranking samples. |
| Fair comparison | Preparation and equipment changes remain identifiable rather than hidden in the result. |
| Supply limit | Qualified code, feed range and practical preparation support the order decision. |