Flux enhancement by using helical baffles in ultrafiltration of suspended solids [An article from: Desalination]
Book Details
Author(s)N. Ghaffour, R. Jassim, T. Khir
PublisherElsevier
ISBN / ASINB000RQZ0FW
ISBN-13978B000RQZ0F2
AvailabilityAvailable for download now
Sales Rank99,999,999
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Desalination, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
The main reason for the flux decline during the initial period of all filtration processes is the usual phenomena of concentration polarization and fouling. After this stage follows the cake filtration process that allows the obtaining of the steady state flux. The solute accumulated on the membrane surface forms a high concentration gel layer, which increases the effective membrane thickness and so reduces its hydraulic permeability. Different techniques are used to reduce this formation and use of helical baffles inside the membrane element is one of such techniques. The selection of appropriate helical baffle is vital to get improved permeation flux with minimum pressure drop for cross-flow feed. The number of helices/unit length has a considerable influence on the selected helical baffle. All experiments have been conducted with an inorganic tubular ultrafiltration membrane for filtering a supernatant from activated sludge plant consisting of suspended and biological solids. The influence of the operational parameters is studied in this paper. Nevertheless, the feed temperature and the concentration were kept constant at the industrial values. We found 1 bar as an optimal pressure, above this pressure the permeation flux decreases, contrarily to several works, which observe a plateau after certain value of pressure. Progressive fouling can be limited by use of helical baffles in the filtration element operated at low pressures and the flocculation of particles is reduced. On the other hand, we have found that the influence of Reynolds number inside the membrane tube and the feed flow-rate are similar to other studies that used different helical baffles.
Description:
The main reason for the flux decline during the initial period of all filtration processes is the usual phenomena of concentration polarization and fouling. After this stage follows the cake filtration process that allows the obtaining of the steady state flux. The solute accumulated on the membrane surface forms a high concentration gel layer, which increases the effective membrane thickness and so reduces its hydraulic permeability. Different techniques are used to reduce this formation and use of helical baffles inside the membrane element is one of such techniques. The selection of appropriate helical baffle is vital to get improved permeation flux with minimum pressure drop for cross-flow feed. The number of helices/unit length has a considerable influence on the selected helical baffle. All experiments have been conducted with an inorganic tubular ultrafiltration membrane for filtering a supernatant from activated sludge plant consisting of suspended and biological solids. The influence of the operational parameters is studied in this paper. Nevertheless, the feed temperature and the concentration were kept constant at the industrial values. We found 1 bar as an optimal pressure, above this pressure the permeation flux decreases, contrarily to several works, which observe a plateau after certain value of pressure. Progressive fouling can be limited by use of helical baffles in the filtration element operated at low pressures and the flocculation of particles is reduced. On the other hand, we have found that the influence of Reynolds number inside the membrane tube and the feed flow-rate are similar to other studies that used different helical baffles.
