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.