Theory 17/Sherwood Number/Dialysis
Clearance Is a Sherwood
The claim
Solute clearance in dialysis is set by the Sherwood number of the membrane module, so a larger membrane with poor flow distribution clears less than a smaller well-distributed one.
01Mechanism
Clearance requires solute to reach the membrane surface; concentration polarisation reduces the effective driving force at high flux.
02Prediction
Clearance should track Sherwood rather than area.
03Refutation
Clearance tracking membrane area would remove the transfer coefficient.