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Vitold Bakhir Electrochemical Systems and Technologies

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 characteristicsFEM-1FEM-2FEM-3
FEM module weight, g220200130
Number of seal rings, pcs.10104
Number of anode bushings, pcs.222
Number of cathode bushings, pcs.002
Number of collectors, pcs.220
Complexity of FEM module assemblyHighMediumLow
Complexity of RPE-L -type reactor assemblyMediumMediumLow
Compactness of RPE-L reactorSatisfactory.SatisfactoryGood
Complexity of RPE-M-type reactor assemblyHighSatisfactoryLow
Compactness of RPE-M reactorUnsatisfactoryUnsatisfactoryGood
Complexity of RPE-F –type reactor assemblyHighHighLow
Compactness of RPE-F reactorUnsatisfactoryUnsatisfactoryGood
Possibility of RPE-S–type reactor assemblyNoNoYes
Possibility of changing configuration of inlet and outlet connections by pivot turn of heads and (or) bushingsNoNoYes
Probability of damaging diaphragm during disassemblyHighHighYes
Possibility of replacing inner electrode without diaphragm removalNoNoYes
Risk of electrochemical anode erosion in the area of liquid feeding (discharge) to the electrode chamber of external electrodeHighMediumNo
Risk of induced polarization of the outer surface of external electrodeHighMediumNo
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)HighMediumno
Accuracy of co-axial diaphragm installation in the interelectrode spaceLowLowHigh
Guaranteed seal-tightness of electrode chambers separation by diaphragm during assemblyNoNoyes
Possibility of spontaneous diaphragm shift resulting from seal ring deformation due to electrochemical process factorsYesYesNo
Probability of deformation, embrittlement, and decrease of electrocatalytic cathode activity as a result of hydrogen pickupHighHighNo
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)YesYesNo
Heat-exchange with the environmentGoodGoodExcellent

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.