Conventional plastic mesh material has been utilized as the feed spacer between spiral wound membranes sheets since they were invented. Under a grant from the Defense Advanced Research Projects Agency (DARPA) printed feed spacer technology was developed. Aqua Membranes Inc. was started in 2011 to commercialize this technology and has subsequently acquired the licenses and developed new intellectual property. In the simplest form, the feed spacer has been replaced by applying material directly on the membrane surface. Performance of these elements in laboratory and field conditions has been compelling. Production capability is in development. For elements with 12โ membrane leaf width it was estimated that up to twice as much membrane surface and thus twice as much permeate could be achieved with printed spacers. Pilot tests of these elements has demonstrated these improvements. With more membrane area versus conventional elements, permeate flow can be significantly improved with no change in differential pressure from the feed to reject end of the element. Additionally, since many applications using smaller elements are not sensitive to pressure drop, spacer thickness can be as little as 5-6 mils thick to maximize surface area in an element. In order to maintain similar pressure loss from feed to reject compared to mesh construction in 40โ long elements, the feed spacer height cannot be reduced as much as it can for shorter elements, even with spacer patterns that provide minimal flow restriction. However, early calculations estimated that elements with 40โ membrane leaf width could still demonstrate up to 40% more permeate flow versus conventional mesh spacer elements while maintaining equivalent pressure loss feed to reject.
This presentation is available to AMTA Members only.
Speaker
- Rodney Herrington
Company
- Aqua Membranes Inc.
Event
- AMTA/AWWA Membrane Technology Conference, West Palm Beach, FL
Session
- AMTA/AWWA Membrane Technology Conference
Date
- 07/20/21
Media
Keywords
- CFD, 3D Printed Spacers, Spiral Wound Membranes
Reference
- 9710-DP2659