The LFNano™ comes in several standard systems and multiples of these systems can be run in parallel to achieve larger capacities. The LFNano™ systems come in 20 centimeter (8 inch) diameter vessels currently with larger (and smaller diameters available on custom orders). The standard LFNano™ system come in odd numbers of pressure vessels from 3 to 11 and from 1 to 3 elements tall. The part number nomenclature is as follows:
LFN-[# vessels]20[elements tall]
So LFN-7202 is seven (7) vessels, each of 20 centimeters in diameter (8 inch) and two elements per vessel. The following table shows the dimensions and capacity of each standard system as well as the range of capacities from low to high flux applications.
|
CAPACITY (m3/d) |
Dimensions (meters) |
||||
|
LOW Flux |
HIGH Flux |
Length |
Width |
Height |
|
| LFN-3201 |
11 |
19 |
1.3 |
1.2 |
1.8 |
| LFN-5201 |
18 |
32 |
1.6 |
1.2 |
1.8 |
| LFN-7201 |
25 |
45 |
1.9 |
1.2 |
1.8 |
| LFN-9201 |
32 |
58 |
2.2 |
1.2 |
1.8 |
| LFN-11201 |
40 |
71 |
2.5 |
1.2 |
1.8 |
| LFN-3202 |
22 |
39 |
1.3 |
1.2 |
2.8 |
| LFN-5202 |
36 |
65 |
1.6 |
1.2 |
2.8 |
| LFN-7202 |
50 |
90 |
1.9 |
1.2 |
2.8 |
| LFN-9202 |
65 |
116 |
2.2 |
1.2 |
2.8 |
| LFN-11202 |
79 |
142 |
2.5 |
1.2 |
2.8 |
| LFN-3203 |
32 |
58 |
1.3 |
1.2 |
3.8 |
| LFN-5203 |
54 |
97 |
1.6 |
1.2 |
3.8 |
| LFN-7203 |
75 |
136 |
1.9 |
1.2 |
3.8 |
| LFN-9203 |
97 |
175 |
2.2 |
1.2 |
3.8 |
| LFN-11203 |
119 |
213 |
2.5 |
1.2 |
3.8 |
Membrane Selection
The LFNano™ has six different nanofiltration (NF) membranes from which to choose. They are described by their rejection of magnesium sulfate (MgSO4) and sodium chloride (NaCl) under certain test conditions. The range of NF membranes available on the LFNano™ are shown in the table below.
| Membrane |
% MgSO4 Rejection |
% NaCl Rejection |
Difference % |
| EPWS NF6A |
99.5 |
90.0 |
9.5 |
| EPWS NF5A |
99.0 |
55.0 |
44.0 |
| EPWS NF4A |
98.5 |
35.0 |
63.5 |
| EPWS NF3A |
99.5 |
40.0 |
59.5 |
| EPWS NF2A |
99.5 |
46.0 |
53.5 |
| EPWS NF1A |
85.0 |
15.0 |
70.0 |
The test conditions for the standard membrane performance tests rarely approximate real world conditions but are used to give people an indication of a membrane’s performance. The difference between the rejection of magnesium sulfate and sodium chloride is important because the monovalent ions like sodium and chloride will exert far more osmotic pressure on a membrane system than the polyvalent ions like magnesium and sulfate. Thus the lower rejection of the monovalent ions is important for a low cost simple system. As a comparison, most reverse osmosis (RO) membranes reject over 95% monovalent ions and over 99% of polyvalent ions.
