Monopolar electrode configurations

Electrode plates or grids are assembled in stack of cells (see Fig. 2). There is no membrane separation between the electrodes. The electrodes are inserted inline directly into the water flow after the filtering unit. Monopolar, bipolar, and combined bipolar-monopolar electrode configurations are used. The required maximum chlorine production rate, for residential pools 2-3 g of CI2 per hour per 10 m of water, defines the size and number of cells. 

In the electrolysis zone, the electrochemical reactions take place. Two basic electrode configurations are used (/) monopolar cells where the same cell voltage is appHed to all anode/cathode combinations and (2) bipolar cells where the same current passes through all electrodes (Eig. 4). To minimize the anodic oxidation of OCL , the solution must be quickly moved out of this zone to a reaction zone. Because the reaction to convert OCk to CIO (eq. 

Electrochemical cells, be they for electrolysis to generate products or for producing electricity (e.g., batteries, fuel cells), fall into two broad categories with respect to the electrode configuration, monopolar and bipolar cells. In a monopolar cell, there are typically many anode and cathode assembUes that are electrically in parallel with each other. Thus, a monopolar cell is typically a high current cell compared to most bipolar cells. In the typical DC circuit configuration, monopolar cells are connected in series by intercell conductors. 

In principle the chlorate technologies differ with respect to electrode configuration (monopolar/bipolar), materials of construction and whether the operations of electrolysis, heat exchange and chemical conversion to chlorate are made in separate vessels or combined in single or double vessel systems [3]. 

Cell geometry, such as tab/terminal positioning and battery configuration, strongly influence primary current distribution. The monopolar constmction is most common. Several electrodes of the same polarity may be connected in parallel to increase capacity. The current production concentrates near the tab connections unless special care is exercised in designing the current collector. Bipolar constmction, wherein the terminal or collector of one cell serves as the anode and cathode of the next cell in pile formation, leads to gready improved uniformity of current distribution. Several representations are available to calculate the current distribution across the geometric electrode surface (46—50). 

There are two types of multielectrode reactor monopolar and bipolar cells, as shown in Fig. 15.2. The bipolar configuration has the advantage that the electrical circuit has only to be linked at the ends of the electrode pile the disadvantage is limitation to certain electrode materials when the anode and cathode are of the same material or when they can be easily glued to each other. 

Golder, A.K., Samanta, A.N., Ray, S. (2007). Removal of Cr31 by electrocoagulation with multiple electrodes biopolar and monopolar configurations. J. Hazard. Mater. 141, 653-661. 

Parallel-plate flow cells Most electrochemical flow cells are based on a parallel-plate electrode design with either horizontal or, more commonly, vertical electrodes in a monopolar or bipolar configuration (see Figure 26.12). With vertical electrodes, the cell is usually constructed in a plate-and-frame arrangement and mounted on a filter press. 

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