Method of hypochlorite production and related sea water electrolyzer with anti scale implemen

Abstract

A significant decrement of the rate of accumulation of scale on electrode and other inner surfaces of a sea water electrolyzer of an electro-chlorination plant, is achieved by intermittently ejecting pressurized sea water through arrays of nozzles that produce energetic (high speed) jets adapted to encroach deep inside the interelectrodic gap spaces of an elongated pack of planar parallel interleaved electrodes. The kinetic energy of the jets is gradually absorbed by the process liquid flowing through the gap spaces from the inlet end to the outlet end of the tubular casing of the electrolyzer containing the elongated electrode pack. The input of kinetic energy in a transverse or inclined direction of encroachment of the jets in the liquid flowing in the gap spaces disrupt the laminar flow causing an energetic turbulence in the interelectrodic body of liquid which effectively hinder a stable accumulation of scale, a good portion of which is swept by the liquid stream out of the electrolyzer into drains in the lower part of electrolyzer.

1 . A process of electrolysis of sea water or equivalent saline water to produce hypochlorite therein in at least an electrolyzer having a plurality of spacingly interleaved vertically held planar anodes and cathodes defining interelectrodic gap spaces there between, through which said sea water or equivalent saline water is forced to flow at a given flow rate, constituting a multi electrode pack assembly contained inside a tubular casing of the electrolyzer, comprising the step of intermittently ejecting, through a plurality of nozzles disposed at regular intervals along the whole length of at least the top side of said pack assembly, pressurized water, sea water or equivalent saline water, jets of which are directed towards said interelectrodic gap spaces, orthogonally and/or at an inclination to the streaming direction of sea water or equivalent saline water forced to flow therein. 
     
     
         2 . The process of  claim 1 , wherein the orthogonally directed jets disrupt laminar liquid flow in said interelectrodic gap spaces. 
     
     
         3 . The process of  claim 1 , wherein the liquid being ejected is at a pressure comprised between 5 and 10 N/m 2 . 
     
     
         4 . The process of  claim 1 , wherein the ratio between the cumulative flow rate of ejection through said plurality of nozzles and the flow rate of said forced flow is comprised between 0.2 and 0.6. 
     
     
         5 . The process of  claim 1 , wherein said jets directed into said interelectrodic gap spaces are simultaneously ejected from atop and from underneath said pack assembly. 
     
     
         6 . An electrolyzer system for electrolyzing sea water or equivalent saline water to produce hypochlorite, the electrolyzer having a plurality of vertically held, spacingly interleaved planar anodes and cathodes defining interelectrodic gap spaces there between and constituting a multi electrode pack assembly contained inside a tubular casing of the electrolyzer through which said sea water or equivalent saline water is forced to flow at a given flow rate, further comprising:
 at least a linear array of nozzles at regular intervals along a distributor pipe extending inside said casing for the whole length of at least the top side of said multi electrode pack assembly;   an intermittent external source of pressurized water, sea water or equivalent saline water, connected to said internal distributor pipe for ejecting from said nozzles jets directed toward said interelectrodic gap spaces, orthogonally to the streaming direction of sea water or equivalent saline water forced to flow therein.   
     
     
         7 . The electrolyzer of  claim 6 , further comprising at least a second linear array of nozzles at regular intervals along a second distributor pipe extending inside said casing for the whole length of the bottom side of said multi electrode pack assembly for simultaneously ejecting jets from atop and from underneath said pack assembly.