Effluent purifying device

Abstract

Liquids such as waste water are clarified in a compact unit consisting of a conditioning stage and of a solid/liquid separating stage. In order to allow the liquids to be clarified as completely as possible in a coherent step, the downward flowing suspension under the influence of gravity is forcibly subjected to a substantially vertical acceleration superimposed on the force of gravity. Preferably, the suspension is subjected to a combination of mechanical, magnetic and electric forces. Consequently, not only a largely complete clarification of the liquid is obtained, even when said liquid entrains the most different groups of substances, but also the dwelling time during the solid/liquid separation is shortened, and the dimensions of the clarification reactor are relatively reduced.

1 . An effluent purification plant comprising a clarification tank ( 2 ) characterized in that it includes: 
 a pump ( 21 ,  50 ) delivering the effluent in a pulsed manner into a chamber ( 20 ) placed on the upper face of the clarification tank ( 2 );    at least one metering pump ( 22 ,  23 ,  24 ) for adding an effluent coagulating or flocculating reactant; and    a pipe ( 25 ) taking the effluent laden with reactant(s) from said chamber into the bottom part of a flocculation vessel ( 12 ) placed inside the clarification tank, in which vessel a sludge bed forms, the effluent flowing upward through said bed and being clarified in contact with the latter.    
     
     
         2 . The effluent purification plant as claimed in  claim 1 , characterized in that the flocculation vessel ( 12 ) comprises a frustoconical upper part ( 13 ) extended by a cylindrical lower part ( 14 ) into which the pipe ( 25 ) runs.  
     
     
         3 . The effluent purification plant as claimed in  claim 1  or  claim 2 , characterized in that the pipe ( 25 ) comprises a first tube ( 26 ), one of the ends of which runs into the chamber ( 20 ) and the other end of which is provided with radial homogenizing openings ( 28 ) and a second tube ( 27 ), of larger diameter than the diameter of the first tube ( 26 ), the upper end of which covers the homogenizing openings ( 28 ) of the first tube and the lower end of which runs into the bottom part of the frustoconical vessel ( 12 ).  
     
     
         4 . The effluent purification plant as claimed in one of  claims 1  to  3 , characterized in that the lower part of the clarification tank ( 2 ) has a frustoconical part ( 4 ) which receives the sludge spilling over the flocculation vessel.  
     
     
         5 . The effluent purification plant as claimed in one of  claims 1  to  4 , characterized in that in that a pump ( 8 ) extracts the sludge collected in the frustoconical part of the clarification vessel.  
     
     
         6 . The effluent purification plant as claimed in one of  claims 1  to  5 , characterized in that calibrated openings ( 3 ) are provided in the upper part of the clarification tank ( 2 ) so as to allow the clarified effluent to be poured into a storage tank surrounding the clarification tank ( 2 ).  
     
     
         7 . The effluent purification plant as claimed in one of  claims 1  to  6 , characterized in that the lower end of the delivery pipe ( 25 ) has a divergent frustoconical section.  
     
     
         8 . The effluent purification plant as claimed in one of  claims 1  to  7 , characterized in that a filter material ( 8 ) is placed between the clarification tank ( 2 ) and the storage tank ( 1 ), the clarified effluent flowing through said filter material before being stored in the bottom part of the storage tank ( 1 ).  
     
     
         9 . The effluent purification plant as claimed in one of  claims 1  to  8 , characterized in that the metering pumps ( 22 ,  23 ,  24 ) introduce reactants into the bottom part of the chamber ( 2 ), upstream of a static mixer ( 11 ) placed on an effluent feed pipe ( 10 ), and into the bottom of the cylindrical part of the flocculation vessel, respectively.  
     
     
         10 . The effluent purification plant as claimed in one of  claims 1  to  9 , characterized in that it includes: 
 a filtration vessel ( 60 ) containing a filter material placed between the chamber ( 20 ) and the flocculation vessel ( 12 );  
 a wall ( 51 ) located between the flocculation vessel ( 12 ) and the filtration vessel ( 20 ); and  
 a discharge pipe ( 56 ), of larger diameter than the delivery pipe ( 25 ) and coaxial with the latter, extending between the wall ( 51 ) and the filtration vessel ( 20 ).  
 
     
     
         11 . The effluent purification plant as claimed in  claim 10 , characterized in that the upper edge of the frustoconical part ( 13 ) of the flocculation vessel ( 12 ) is contiguous with the internal face of the tank ( 2 ).  
     
     
         12 . The effluent purification plant as claimed in  claim 10  or  claim 11 , characterized in that the filtration vessel ( 60 ) has, on its lower face, openings ( 61 ) protected by strainers ( 62 ) allowing the filtered water to flow out.  
     
     
         13 . The effluent purification plant as claimed in one of  claims 1  to  12 , characterized in that a pump ( 36 ) sucks the clarified effluent out of the storage tank ( 1 ) and introduces it into at least one annular chamber ( 31 ), placed on the external face of the storage tank, containing a granulate that fixes bacteriological elements.  
     
     
         14 . The effluent purification plant as claimed in  claim 13 , characterized in that the annular chambers are four in number ( 31 ,  32 ,  33 ,  34 ), each communicating with the one adjacent thereto via a conduit ( 35 ).  
     
     
         15 . The effluent purification plant as claimed in either of claims  13  and  14 , characterized in that a recovery pump ( 39 ) sucks up the clarified effluent in the upper annular chamber ( 34 ) and reinjects it into the lower chambers ( 31 ,  32 ,  33 ).  
     
     
         16 . The effluent purification plant as claimed in either of claims  1  and  15 , characterized in that the storage tank ( 1 ), the clarification tank ( 2 ), the flocculation vessel ( 12 ) and the annular chambers are made of plastic.