Laboratory-scale finned-rotor impeller for dialysis

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Mass Transfer

Background:

• Dialysis is crucial for fluid purification, often using hollow-fibre dialysers with large priming volumes.
• Controlling priming volumes is essential for developing laboratory techniques.
• Dialysis tubing (DT) offers controllable priming volumes but requires efficient mixing for adequate mass transfer.

Purpose of the Study:

• To assess a novel impeller-based dialyser designed for use with dialysis tubing (DT).
• To evaluate the device's ability to facilitate mass transfer and control fluid osmolality.
• To establish experimental correlations between impeller rotation speeds and operational parameters.

Main Methods:

• Utilized an impeller-based dialyser with finned rotors for simultaneous mixing of dialysate and DT content.
• Conducted mass-transfer trials using saline and washed-packed erythrocytes against hypotonic and hypertonic dialysate.
• Measured the DT's overall mass-transfer coefficient and established correlations between impeller rotation speeds (omega H and omega V).

Main Results:

• The impeller-based dialyser demonstrated effective mixing and mass transfer.
• Fluid osmolality within the DT exhibited an exponential decay pattern.
• The vertical rotor speed (omega V) was found to be significantly dependent on horizontal impeller speed (omega H) and submergence depth.

Conclusions:

• The developed impeller-based dialyser is a viable laboratory tool for fluid dialysis with controllable priming volumes.
• The device ensures efficient mass transfer through effective fluid mixing.
• Understanding the relationship between impeller speeds and submergence depth is key to optimizing dialysis performance.