Method and arrangement for clarifying green liquor

Abstract

Green liquor clarification comprising filtering of a flowing suspension containing solids, wherein the suspension is brought into contact with a first filter unit ( 4 ), said 5 filter unit ( 4 ) comprising one or several filter elements ( 12 ) comprising one or several filter bodies ( 3 ) having filter channels ( 33 ) within the filter bodies ( 3 ) with a filtering layer ( 32 ), a part of the suspension is forced to pass through the filtering layer ( 32 ) from a first/inner surface ( 32 A) to a second/outer surface ( 32 B) of the filtering layer ( 32 ) forming a filtrate while the solids substantially remains in a residual part of the suspension forming a slurry and where the filtering layer ( 32 ) is made of a membrane material with pores, said pores having a pore size of 0.1-10 micrometer, more preferred 0.1-5 micrometer and most preferred 0.2-1.0 micrometer.

1 - 38 . (canceled) 
     
     
         39 . A method for clarifying green liquor comprising:
 filtering a flowing suspension containing solids, wherein the suspension is brought into contact with a first filter unit, said filter unit comprising one or several filter elements, comprising one or several filter bodies having filter channels within the filter bodies with a filtering layer, a part of the suspension is forced to pass through the filtering layer from a first/inner surface to a second/outer surface of the filtering layer forming a filtrate while the solids substantially remains in a residual part of the suspension forming a slurry wherein the filtering layer comprises a membrane material having pores, and said pores having a pore size of 0.1-10 micrometer.   
     
     
         40 . The method according to  claim 39 , wherein the pores have a size of 0.2-1.0 micrometer. 
     
     
         41 . The method according to  claim 39 , wherein said suspension is forcibly caused to flow into said filter body. 
     
     
         42 . The method according to  claim 39 , wherein the flowing suspension has a Reynolds Number between 10,000-45,000. 
     
     
         43 . The method according to  claim 42 , wherein the flowing suspension has a Reynolds Number between 12,000-17,000. 
     
     
         44 . The method according to  claim 39 , wherein said membrane material is ceramic. 
     
     
         45 . The method according to  claim 39 , wherein the suspension is forcibly caused to flow into said filter unit by a pump. 
     
     
         46 . The method according to  claim 39 , wherein said filter unit is connected to an already existing cleaning unit for green liquor. 
     
     
         47 . The method according to  claim 46 , wherein said filter unit is arranged as a first filtering step before final cleaning of the remaining slurry in the already existing cleaning unit. 
     
     
         48 . The method according to  claim 46 , wherein the filter unit is arranged to filter already cleaned green liquor. 
     
     
         49 . An arrangement for green liquor clarification comprising filtering of a flowing suspension containing solids, wherein the suspension is brought into contact with at least one filter unit, said filter unit comprising one or several filter elements, comprising one or several filter bodies having filter channels within the filter bodies with a filtering layer, a part of the suspension is forced to pass through the filtering layer from a first/inner surface to a second/outer surface of the filtering layer forming a filtrate while the solids substantially remains in a residual part of the suspension forming a slurry wherein the filtering layer comprises a membrane material having pores, and said pores having a pore size of 0.1-10 micrometer. 
     
     
         50 . The arrangement according to  claim 49 , wherein said pores have a pore size of 0.2-1.0 micrometer. 
     
     
         51 . The arrangement according to  claim 49 , wherein said suspension is forcibly caused to flow into said filter body. 
     
     
         52 . The arrangement according to  claim 49 , wherein the flowing suspension has a Reynolds Number between 10,000-45,000. 
     
     
         53 . The arrangement according to  claim 52 , wherein the flowing suspension has a Reynolds Number between 12,000-17,000. 
     
     
         54 . The arrangement according to  claim 49 , wherein said membrane material is ceramic. 
     
     
         55 . The arrangement according to  claim 49 , wherein the suspension is forcibly caused to flow into said filter unit by a pump. 
     
     
         56 . The arrangement according to  claim 49 , wherein said filter unit is connected to an already existing cleaning unit for green liquor. 
     
     
         57 . The arrangement according to  claim 56 , wherein said filter unit is arranged as a first filtering step before final cleaning of the remaining slurry in the already existing cleaning unit. 
     
     
         58 . The arrangement according to  claim 56 , wherein the filter unit is arranged to filter already cleaned green liquor.