A device for electrochemical treatment of water
RF Patent # 2078737. Filed 26.05.1994, published 10.05.97.
Bakhir V.M. and Zadorozhny Yu.G.
Flow-through electrochemical modular reactor – FEM-3 module. FEM-3 module, while very similar to FEM-2 module in the principle of its application in electrochemical systems, technically has an absolutely new design, and essentially differs from its prototype – FEM-2 module. Unlike FEM-2 and FEM-1 modules, FEM-3 module is devoid of problems arising in connection with the presence of bi-polar areas on the surface of external electrode, and it surpasses FEM-1 and FEM-2 modules in its mechanic, hydraulic and electrochemical reliability and durability. The Table below presents principal differences between FEM-1, FEM-2 and FEM-3 modules, which demonstrate advantages of FEM-3 module as a commercial standard all-purpose device for various types of electrochemical systems.
FEM-3 module and RPE reactors made up of units of FEM-3 modules have the following typical feature. FEM-3 modules can be used to implement any technological processes developed for FEM-1 and FEM-2 modules. Simultaneously, performance characteristics of these processes become better. However, FEM-1 and FEM-2 modules cannot be used in process flow sheets developed for FEM-3 modules either due to reasons making such replacement technically and technologically impossible, or because performance characteristics of processes implemented with the help of FEM-1 or FEM-2 modules prove to be worse than when using FEM-3 modules.
Principal technical and technological differences of FEM-1, FEM-2 and FEM-3 modules
|
Technical and technological characteristics |
FEM-1 |
FEM-2 |
FEM-3 |
|
FEM module weight, g |
220 |
200 |
130 |
|
Number of seal rings, pcs. |
10 |
10 |
4 |
|
Number of anode bushings, pcs. |
2 |
2 |
2 |
|
Number of cathode bushings, pcs. |
0 |
0 |
2 |
|
Number of collectors, pcs. |
2 |
2 |
0 |
|
Complexity of FEM module assembly |
High |
Medium |
Low |
|
Complexity of RPE-L -type reactor assembly |
Medium |
Medium |
Low |
|
Compactness of RPE-L reactor |
Satisfactory. |
Satisfactory |
Good |
|
Complexity of RPE-M-type reactor assembly |
High |
Satisfactory |
Low |
|
Compactness of RPE-M reactor |
Unsatisfactory |
Unsatisfactory |
Good |
|
Complexity of RPE-F –type reactor assembly |
High |
High |
Low |
|
Compactness of RPE-F reactor |
Unsatisfactory |
Unsatisfactory |
Good |
|
Possibility of RPE-S–type reactor assembly |
No |
No |
Yes |
|
Possibility of changing configuration of inlet and outlet connections by pivot turn of heads and (or) bushings |
No |
No |
Yes |
|
Probability of damaging diaphragm during disassembly |
High |
High |
Yes |
|
Possibility of replacing inner electrode without diaphragm removal |
No |
No |
Yes |
|
Risk of electrochemical anode erosion in the area of liquid feeding (discharge) to the electrode chamber of external electrode |
High |
Medium |
No |
|
Risk of induced polarization of the outer surface of external electrode |
High |
Medium |
No |
|
Probability of decreased concentration of heterogeneous structures carriers of active charged particles in areas of changed configuration of electric lines of force (in the outlet openings of external electrode) |
High |
Medium |
no |
|
Accuracy of co-axial diaphragm installation in the interelectrode space |
Low |
Low |
High |
|
Guaranteed seal-tightness of electrode chambers separation by diaphragm during assembly |
No |
No |
yes |
|
Possibility of spontaneous diaphragm shift resulting from seal ring deformation due to electrochemical process factors |
Yes |
Yes |
No |
|
Probability of deformation, embrittlement, and decrease of electrocatalytic cathode activity as a result of hydrogen pickup |
High |
High |
No |
|
Existence of critical zones of liquid convective flow blockage in external electrode chamber (three phases “gas bubbles-charged metal-liquid” in narrow clearances at the inlet and outlet) |
Yes |
Yes |
No |
|
Heat-exchange with the environment |
Good |
Good |
Excellent |
In the process of further practical work with FEM-3 modules it was realized that the development of a reliable, all-purpose and easy-to-use electrochemical reactor marked the birth of the technology of electrochemical activation in particular, and the technology of “personal” applied electrochemistry in general.