Membrane Telescoping

Describes the shifting of the internal mechanical components of a spiral-wound element. It is most often caused by excessive fouling of the membrane, distorting the feed channels and disrupting even flow distribution allowing the feed spacers and membrane leaves to slip, usually in a conical pattern.

Symptoms of telescoping include:

• Difficulty cleaning due to permanent flow pattern disruption, leading to unrecoverable membrane performance over time
• Loss in permeate quality from the shifting of the feed spacers, particularly in the presence of abrasive material or creasing of the membrane leaves