Patent ID: 11858870
Assignee: DARI-TECH, INC.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  Y | IPC C

Claim 12:
13. A digester system comprising:
a primary digester tank for digestion of a primary feed material into biogas and secondary feed material, a primary tank volume of primary feed material present during digestion defining a primary feed material level;
a secondary digester tank for receiving a secondary tank volume of the secondary feed material, a secondary tank volume of secondary feed material present during digestion defining a secondary feed material level;
a first conduit communicating between a digester tank lower tank opening the primary digester tank defines and a secondary tank lower tank opening the secondary digester tank defines, where the primary digester tank lower tank opening is below the primary feed material level and the secondary digester tank lower tank opening is below the secondary feed material level;
a second conduit communicating between a primary tank upper opening the primary digester tank defines and a secondary digester tank upper opening the secondary digester tank defines, where the primary digester tank upper opening is located above the primary feed material level and the secondary digester tank upper opening is located above the secondary feed material level;
a flow control valve configured to allow a flow of fluid through the first conduit from the primary digester tank to the secondary digester tank at a first flow rate during an interval when the primary tank head pressure is sufficiently greater than the secondary tank head pressure so as to motivate settled solid matter in the primary tank through the first conduit into the secondary digester tank;
a pump is operatively connected to the secondary digester tank and a separator, which in operation, is configured to continuously remove the secondary feed material portion from the secondary digester tank at a second flow rate to feed the separator;
wherein;

the first flow rate is greater than the second flow rate; and
the separator separates the secondary feed material portion pumped from the secondary digester tank into liquid and solid components.