FLOW THROUGH ELECTROCHEMICAL MODULAR ELEMENTS

History of the Flow Through Electrochemical Modular Elements started in 1989 when Vitold Bakhir and Yuri Zadorozhny developed the first industrial FEM-1 element (British patent GB 2 253 860).

At the same time V.Bakhir and Yu.Zadorozhny founded manufacturing company “Laboratory of Electrotechnology Limited” (LET, Ltd) with the main purpose of manufacturing of the Flow through Electrochemical Modular Elements.

1000 FEM-1 elements have been manufactured by LET, Ltd. The first FEMs were tested in various electrochemical devices and demonstrated high technical and economic efficiency.

In 1992 the authors developed industrial standard of the Flow through Electrochemical Modular Element known as FEM-2. Essential technical features of this Element are protected by Russian Patent # 2042639. From 1992 to 1997 the two companies (LET,Ltd and Joint Venture “Emerald”) have manufactured about 60 thousand FEM-2 elements.

In 1994 V.Bakhir and Yu.Zadorozhny developed industrial standard of the Flow through Electrochemical Modular Element named FEM-3 element. Engineering solutions realized in this Element are protected by Russian patent # 2078738. Within the period from 1994 to 2008 LET,Ltd manufactured over 700 000 FEM-3 elements. Further development and improvement of the FEM design and technology of it’s practical applications in various electrochemical devices furthered the development of the new types of elements known as FEM-4 (developed in 1998, Russian patent # 2145940), FEM-7 (developed in 2000, Russian patent # 2176989), FEM-9 (developed in 2004, Russian patent # 2270885). All engineering solutions protected by the above mentioned Patents contain numerous secrets of manufacture which are not given in the Patents’ descriptions therefore attempts of copying FEMs by unfair companies or individuals have always resulted in appearing in the market of low-grade and short-lived products.

By the end of 2008 LET,Ltd stopped manufacture of the Flow through Electrochemical Modular Elements FEM-3, FEM-4, FEM-7 and FEM-9 and Flow through Electrochemical Reactors incorporating the above elements as the team of authors headed by and with immediate participation of V.Bakhir and Yu. Zadorozhny developed MB-11 and MB-26 elements which possess essential technical, technological and functional advantages over FEM elements. Let, Ltd commenced manufacture of the new MB elements from 2009. MB elements are protected by unified patent which for the first time on micro level includes all basic differences of electrolytic cells allowing to realize design of technical electrochemical systems of any capacity and any complexity in accordance with the laws of living organisms formation from separate cells.

Developed and protected by the Patent set of features and methods embracing all spectrum of design values and geometrical parameters provides unique properties of the new Electrochemical Modular Elements: possibility of realization of ion-selective diaphragm electrolysis for electrolytes solutions with any degree of mineralization (from distilled water to fat solutions) using the new elements both as separate device or as a unit of hydraulically parallel and/or series connected electrochemical diaphragm reactors with various flow rates, flow directions (parallel and counter) and pressure in cathode and anode chambers.

New features protected by Russian Patent and International Patent Application (Patent Cooperation Treaty PCT/RU2008/000740P), provide possibility of development of compact modular electrochemical diaphragm reactors with various output capacity, containing various design, technical and technological particular features being optimal for realization of specific technological or technical purposes. Numerous technical and technological secrets not included in the Patent’s description serve as a reliable protection against copying. The team of authors of the new Patent took decision on naming the new element after the name of the founder of ECA technology Vitold Bakhir. This is an additional protection against illegal copying and illegal avowal (announcement) of belonging in any form to the said product by unfair individuals and companies. Every Modular Electrochemical Element manufactured by LET, Ltd starting from 2009 will have a corresponding stamp with the name of the element in Russian and English , number of the protective document and the name of the manufacturing company – “Laboratory of Electrotechnology, Ltd”

Attached below are some characteristic designs from PCT/RU2008/000740.

Fig. 1. Specific conductivity (1) of aqueous solutions of nonorganic substances: acids, salts, bases, and mean distances (2) between ions of these electrolytes depending on concentration. MB elements areas of application.

Fig. 3. Section of MB element operating chamber D1 и D2 – accordingly inner and outer anode diameters ; D3 и D4 – accordingly inner and outder diaphragm diameters; D5 и D6 – accordingly inner and outer cathode diameters; Lec – length of the electrode chamber operating part.

Fig. 6. Electric intensity in interelectrode space of MB element
a b e f k l - without diaphragm;
a b c h k l - with ceramic diaphragm from corundum;
a b e d q f k l - with diaphragm from grains of alumina in zirconium oxide glaze (?) stabilized by oxides of rare and rare-earth metals;
0 - m – width of anode chamber;
m-n - thickness of diaphragm;
n - l - width of cathode chamber;

Fig. 2. Ion-selective electrolysis in MB element.

Fig. 4. Distribution of field lines of current density and oxidation potential at microasperities of anodic surface in dilute electrolytes solutions.

Fig. 5. Schematic sketch of microtoroidal (?) flows of solutions in electrode chambers of MB element.

Fig. 7. Dependence of electrode area to solution volume ratio on interelectrode distance for electrolyzers of different types:
1 – chloric electrolyzer with mercury-pool cathode;
2 – filter press electrolyzer;
3 – capillary electrolyzer;
4 – column electrolyzer;
5 – beater electrolyzer;
6 – electrolyzer with fluidizated electrodes;
7 – electrolyzer with poured or porous electrodes;
8, 9 and 10 – МB-11 and МB-26 elements