《应用电化学1-2》.ppt

Some general rules in cell design: 1)????? Simplicity 2)????? Operational convenience and reliability 3)????? Integration and versatility 4)????? Reaction engineering parameters 5)????? Running costs Some decisions in the process of cell design: see p143 Table 2.5 2.6.1?????Cell design 2.6.2 Classification of cells (1) Tank cells or tank-type electrochemical reactors（箱式槽) The tank cell is the classical batch or semi-batch (reactants added and products removed at intervals) reactor of electrochemical technology. The great advantage of the tank cell is the simplicity of construction and the wide range of materials which can be used for the manufacture of the simple components required. It is, however, limited in space-time yield and poorly suited to large scale operation or to a process where control of the mass transport conditions is necessary. (2) Parallel-plate flow cell Most industrial flow cells are based on the parallel-plate electrode configuration and again the electrodes may be horizontal or vertical. With vertical electrodes the cell is usually constructed in a plate-and-frame（板框） arrangement and mounted on a filterpress （压滤）(filterpress-type cell or frame-and-plate cell). Fig. 2.28 Plate-and frame cell (monopolar electrodes) A=anolyte; C=catholyte Advantages of parallel-plate cells: a)????? Simplicity of construction with regard to features such as cell frames, electrode connections and membrane sealing. b)????? Wide availability of electrode materials and separators in a suitable form. c)????? The potential distribution is reasonably uniform. d)????? Mass transport may be enhanced and adjusted using a variety of turbulence promoters and control of the linear electrolyte velocity. e)?????? Scale-up readily achieved by a suitable combination of increased electrode size, using more electrodes and duplicating the cell stack. f)?????? Versatility, with respect to monopolar