Abstract A method and device for removing water from normally difficult to filter suspensions, such as sludge wherein the suspension is disposed in a container having a negatively charged cathodic screen bottom surface and a moveable anode screen specially disposed within the suspension from the bottom cathode surface, together with means for controlling the electric potential between the anode and cathode, as well as the distance therebetween such that the water or other effluent can be removed through the cathode screen bottom surface leaving a cake of higher solids content. Additionally, means is provided for removing the cake formed between the cathode and anode from the suspension and continue the removal of water therefrom, while the cake is out of the suspension environment.
The method of claim 1 wherein said removed cake is led between a screen cathode and an anode, and further comprising: maintaining contact of said cake with said anode and cathode as said cake shrinks due to liquid removal therefrom.
Claim 2
Dependent Claim
26 words
The method of claim 2 wherein said cake rests on said cathode and said anode is controllably moved downwardly toward said cathode as said cake shrinks.
Claim 3
Dependent Claim
69 words
The method of claim 2 wherein the bottom screen cathode of said container is slanted upwardly from below the surface of said suspension to above said surface and comprising: moving said anode parallel to said cathode from below said surface of said suspension to above said surface, and correspondingly moving a means for forcing said formed cake between said anode and cAthode to follow the movement of said anode.
Claim 4
Dependent Claim
78 words
The method of claim 1 wherein said removed cake is held between a screen cathode and an anode, and further comprising: maintaining contact of said formed cake with said anode and cathode, detecting changes in electrical resistance of said formed cake as said cake shrinks due to liquid removal therefrom, and moving said anode toward said cathode in response to said detected changes in resistance to maintain the contact of said formed cake with said anode and cathode.