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The processing function of every OMNIPURE unit is the same – regardless of size. The automated process for generating an oxidant on-demand is simple and proven effective. Operation is semi-continuous, with continuous collection of sewage and cycle processing of the accumulated black and gray water.
Raw sewage is collected via gravity into the system’s V-1 influent collection tank. All Gray water wastes from sinks, showers, and associated sanitary waste systems is also introduced directly into the OMNIPURE unit V-1 influent collection tank via gravity. The V-1 tank incorporates a pear type level switch level detection system. These level switches initiate the start and stop sequences of the OMNIPURE unit when the unit is in the “Auto” mode. When the V-1 tank level rises, the level switches are actuated and the treatment unit starts.
Once the liquid level in the unit’s V-1 tank reaches the “Start” level point, the sewage is finely ground, or macerated, through a specially designed macerator. From the macerator discharge, a portion of the macerated sewage is returned to the V-1 tank through a calibrated orifice plate. The remainder of the macerated sewage is then mixed with a controlled amount of seawater to insure proper salinity for optimum operation of the OMNIPURE bookcell. Seawater enters the OMNIPURE unit between the bookcell and the discharge of the macerator via a strainer and flow controller. This flow controller limits the seawater flow to a predetermined value based on the specific treatment capacity of the OMNIPURE unit. The use of calibrated orifice plates and the seawater flow controller allows liquid flow to the bookcell to be maintained at the correct rate.
The OMNIPURE unit oxidizes and disinfects raw sewage by means of an electrochemical reaction in the bookcell. The electrochemical reaction is the result of D.C. voltage applied to specially designed anode and cathode plates (electrodes) within the bookcell. The sewage and seawater slurry from the macerator flows between the charged electrodes. The seawater acts as an electrolyte for DC current flow between the anode and cathode plates. The chloride salts of the seawater are electrolized to form sodium hypochlorite. The electrochemical reaction and the resulting production of sodium hypochlorite kills the harmful coliform bacteria and oxidizes the organic compounds in the sewage stream. One pass through the bookcell kills nearly 100% of resident bacteria and oxidizes between 90 to 95% of the organic compounds found in normal sewage.
The electrical power required to operate the bookcell is derived from the OMNIPURE unit’s internal D.C. power supply. The internal PCB controls the bookcell thru a fixed current. The amount of D.C. current applied to the bookcell determines the amount of sodium hypochlorite produced. This is Factory set.
After the slurry of sewage and seawater has been electrolyzed in the bookcell, the stream is routed into the OMNIPURE unit V-2 residence tank. The stream enters the top of the V-2 tank through a vertical “downcomer” pipe. This pipe is internal to the V-2 tank. The downcomer pipe outlet is near the bottom of the V-2 tank. The downcomer reduces velocity of incoming process stream and encourages degasification. During the electrolysis process, small amounts of hydrogen and other gases are produced as byproducts. The downcomer works in conjunction with a positive vent system to extract gases from the process and send them to the atmosphere.
The V-2 tank is sized to provide a minimum 30-minute retention time between the entry of treated sewage (effluent) at the bottom of the V-2 tank and subsequent discharge from the top of V-2 tank to the sea.
This 30-minute retention time assures that any remaining bacteria will be exposed to the produced hypochlorite and killed and allows for any partially oxidized particles to settle. These particles (consisting mostly of cellulose) are recirculated into the V-1 tank through the blowdown line during the backflush and blowdown maintenance procedure for re-treatment.
After retention in the V-2 tank, the effluent overflows from the top of the V-2 tank and gravity flows to the sea. If this discharge point is under the vessels waterline, the V-2 tank discharge is routed to a centrifugal overboard discharge pump for discharge to the sea.
The electrolytic process naturally generates a minimal amount of hydrogen and carbon dioxide. These byproducts are safely and efficiently discharged into the atmosphere via an air ejector. An optional electrical blower can be supplied for effective dilution of the byproducts if desired.
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