Apparatus and methods for dewatering sludge

An apparatus for dewatering sludge comprising:

• a tank having an internal space divided by a dividing wall into an intake chamber capable of being pressurized and withstanding vacuum, and an extract chamber;
• an intake pipe in fluid communication with the intake chamber with fluid flow therethrough controlled by an intake valve;
• a discharge pipe in fluid communication with the extract chamber with fluid flow therethrough controlled by a discharge valve;
• a transfer pipe providing fluid communication between the intake chamber and the extract chamber, with a first opening near the bottom of the intake chamber, and a second opening near the top of the extract chamber;
• a pump in fluid communication with the intake chamber and capable of selectively creating positive and negative pressure within the intake chamber;
• and
• a screen within the extract chamber positioned between the second opening of the transfer pipe and the discharge pipe;
• wherein an end of the tank adjacent to the extract chamber comprises a door having a rim, and wherein the screen comprises a rim which presses against the rim of the door when the door is closed.