Electrolytic purification system utilizing rapid reverse current plating electrodes

A process for removing foreign matter from water in which it is suspended, comprising the steps of:

• A. providing a plurality of electrodes adjacent to each other to form electrolysis-cell sections therebetween, the electrodes being adapted for application of a potential difference when the electrodes are immersed in water to cause electric current to flow between adjacent electrodes through the water between them;
• B. flowing water having foreign matter suspended therein through the electrolysis cell;
• C. impressing a potential difference between adjacent electrodes to cause electric current to flow therebetween to electrolyze the water forming hydrogen and oxygen bubbles so that the bubbles coat the suspended foreign matter, causing the foreign matter to float to the surface of the water;
• D. separating the foreign matter at the water surface from the water below, thereby reducing the concentration of foreign matter in the water;
• E. protecting the electrodes from the effects of anodic destruction and scale and scum formation by periodically reversing the direction of the electric current flowing between adjacent electrodes for a predetermined period of time, allowing the current flowing between adjacent electrodes to electrolyze the water forming hydrogen and oxygen bubbles to coat the suspended foreign matter, said predetermined period of time is less than the time required for oxide formed on the electrodes to release into the water, so that when the direction of the current is reversed the oxide formed due to anodic breakdown is reduced back to the surface of the electrode while said electrode is a cathode;
• and,
• F. continuing to repetitively reverse the direction of the current for said predetermined time to repeat the process,
• whereby the electrodes are protected from the effects of anodic destruction and scale and scum formation while efficiently removing foreign matter from the water.

An improved electrolytic flotation system for removal of foreign matter from water, the system including,

• a. a plurality of electrodes for immersion in water, and,
• b. means for driving the electrodes causing an electrical current to flow between adjacent electrodes so that one electrode is an anode and another is a cathode causing bubbles to be generated in the water by electrolysis between adjacent electrodes, the bubbles adhering to and floating the foreign matter towards the surface of the water, wherein the improvement comprises:
• current reversing control means for reversing the direction of current flowing between adjacent electrodes, the current reversal occurring at a rate which allows the current to flow between the adjacent electrodes for a predetermined duration of time sufficient to generate bubbles in the water by electrolysis, the predetermined period of time is also sufficient for causing oxidized electrode material formed on the cathode to be reduced onto the surface of the cathode, the predetermined duration of time is insufficient to allow oxidized components of the anode from releasing into the water;
• after the predetermined duration of time has elapsed, the current reversing control means reversing the direction of the current between adjacent electrodes and continually repeating the electrolysis cycle for a desired duration of time,
• whereby the electrodes are protected from the effects of anodic destruction and scale and scum formation while efficiently removing foreign matter from the water.

An electrolytic flotation system for removing foreign matter from water in which foreign matter is suspended comprising:

• A. a means for causing bubbles of gas to be formed within water in a tank containing suspended foreign matter so that the bubbles adhere to the suspended foreign matter causing the foreign matter to float to the surface of the water due to flotation pressure caused by the gas bubbles;
• B. a tapered float concentration zone of decreasing cross sectional area for concentrating the gas bubbles and floated foreign matter above the surface of the water, said tapered float concentration zone terminating in an outlet above the surface of the water,
• whereby the float is ejected from the outlet by the force generated from the flotation pressure of the concentrated gas bubbles rising through the tapered float concentration zone, separating the foreign matter from the water, resulting in an output which contains a low concentration of water;
• said means for causing bubbles of gas to be formed comprises;
• a. a plurality of electrodes for immersion in the water in the tank;
• b. means for driving the electrodes causing an electrical current to flow between adjacent electrodes so that one electrode is an anode and another is a cathode causing bubbles to be generated in the water by electrolysis between adjacent electrodes, the bubbles adhering to and floating the foreign matter towards the surface of the water;
• and,
• c. current reversing control means for reversing the direction of current flowing between adjacent electrodes, the current reversal occurring at a rate which allows the current to flow between the adjacent electrodes for a predetermined duration of time sufficient to generate bubbles in the water by electrolysis, the predetermined period of time is also sufficient for causing oxidized electrode material formed on the cathode to be reduced onto the surface of the cathode, the predetermined duration of time is insufficient to allow oxidized components of the anode from releasing into the water;
• after the predetermined duration of time has elapsed, the current reversing control means reversing the direction of the current between adjacent electrodes and continually repeating the electrolysis cycle for a desired duration of time,
• whereby the electrodes are protected from the effects of anodic destruction and scale and scum formation while efficiently removing foreign matter from the water.