Automated manifold for removing digestate from a lagoon digester

An extraction manifold for extracting digestate from a covered lagoon digester including a digester vessel being shaped generally as a rectangular prism lacking an upward facing face and having a floor sloping generally downward from an intake face to an extraction face of the digester vessel, the intake face and extraction face being each oriented vertically and being situated in opposed relation on a longer horizontal axis and a cover to seal the digester vessel at its upward facing face, the seal and cover in concert to catch and retain a volume of biogas, the extraction manifold comprising:

• a plurality of effluent pipes, each effluent pipe terminating in an extraction nozzle and including an attached independently addressable actuatable valve situated on an opposite end of the effluent pipe from the extraction nozzle, each actuatable valve in communication with a manifold plenum such that actuation of the valve establishes communication between the corresponding extraction nozzle and the manifold plenum, each of the extraction nozzles being situated to draw digestate from the floor generally in a region of the floor adjacent to the extraction face and in proximity to the extraction nozzle when the corresponding attached independently addressable actuatable valves are actuated;
• and
• a valve controller system to generate signals to actuate, in turn, each of the independently addressable actuatable valves to remove digestate from the region of the floor adjacent to the extraction face.

A method for extracting digestate from a covered lagoon digester including a digester vessel being shaped generally as a rectangular prism lacking an upward facing face and having a floor sloping generally downward from an intake face to an extraction face of the digester vessel, the intake face and extraction face being each oriented vertically and being situated in opposed relation on a longer horizontal axis and a cover to seal the digester vessel at its upward facing face, the seal and cover in concert to catch and retain a volume of biogas, the method comprising:

• situating each of a plurality of effluent pipes, each effluent pipe terminating in an extraction nozzle and including one of the plurality of independently addressable actuatable valve, each valve situated on an opposite end of one of the plurality of effluent pipes from the extraction nozzle, each actuatable valve in communication with the manifold plenum such that actuation of the valve establishes communication between the corresponding extraction nozzle and the manifold plenum, each of the extraction nozzles being situated to draw digestate from the floor generally in a region of the floor adjacent to the extraction face and in proximity to the extraction nozzle when the corresponding attached independently addressable actuatable valves are actuated;
• retrieving an algorithm at a valve controller system, the algorithm defining a sequence of activation cycles and activation intervals, the algorithm causing the valve controller system to generate signals to activate the actuatable valves, in turn and in accord with the sequence;
• and
• using the valve controller system to generate the signals in response to the retrieved algorithm thereby to remove digestate from the region of the floor adjacent to the extraction face.