ELECTROCHEMISTRY

Hydropure® electrolyzer by Sespi

HYDROPURE® electrolyser consists of a number of bipolar elements assembled between two end-plates by means of tie rods, forming a filter press type unit.
The bipolar element is a steel frame surrounding a bipolar plate to which electrodes of planar anodes on one side and a set of planar cathodes on the other side.
Both electrodes are made of expanded metal sheet to increase the electrode working area to facilitate the withdrawal of gases from the interelectrodic gap.
Anodes are of heavily nickel plated mild steel, activated to decrease the over voltage, whilst the cathodes are of mild steel, specially activated to increase surface roughness, thus decreasing over voltage.
The diaphragms are made of a specially treated material.
The bipolar elements are assembled so that each set of anodes faces the set of cathodes of the adjacent element. The anodes and cathodes facing each other – which form the electrochemical cell – are separated by ad double diaphragm, this constitutes the particular feature of HYDROPURE® electrolyser.
The intermediate chamber between the two diaphragms, being opened to the atmosphere through a vent-pipe, constitutes an important safety device.
If a diaphragms failure occurs, the danger of intermixing is eliminated, as the gas escaping is immediately released to the atmosphere and visually detected in the vent-pipe. Moreover, the use of a double diaphragms increases gas purity.
The number of bipolar elements of an electrolyser can vary from 4 to 100 according to the production capacity required.
Due to the rated current density, the capacity can also be varied from 40% to 120% by changing the load.