What is the difference between element & system recovery?
Date: Thursday 17 July, 2008
Element recovery: This refers to a single membrane element recovery rate.
System recovery: This refers to a cumulative recovery rate. Click to view the complete answer
Element recovery: This refers to a single membrane element recovery rate. Element recovery = Permeate flow rate of single element / feed flow rate to the single element x 100%.
System recovery: This refers to a cumulative recovery rate. System recovery = cumulative permeate flow rate of membrane elements in a system / feed flow rate to the system x 100%
For example: Suppose there are two parallel pressure vessels and each pressure vessel contains 6 membrane elements. Feed flow to the system is 100 gpm. Since there are two pressure vessels in parallel, feed flow to each vessel is 50 gpm. The first element in each vessel would see 50 gpm of feed. Suppose the first element produces 5 gpm of permeate water and the whole system produces 50 gpm of permeate water. Then, the first element recovery = 5 gpm / 50 gpm x 100% = 10% while the system recovery = 50 gpm / 100 gpm x 100% = 50%