Sludge distribution network

Claim 2

In a sludge digestion facility of the type in which a body of sludge contained within a tank is digested in said tank by bacteria, said body comprising a plurality of quiescent zones near the bottom of said tank, the improvements including a plurality of pipes mounted within said tank, each pipe having an effluent opening into one of said quiescent zones adjacent the floor of said tank, said openings peripherally disposed and spaced apart within said tank, pump means for pumping partially digested sludge derived from said tank, and valve means in communication with said pump means for distributing said partially digested sludge sequentially to only one of said pipes at a time, and for a period sufficient to enable partially digested sludge emerging from the opening of said one of said pipes into its respective quiescent zone, to substantially entirely displace materials which have settled in said respective quiescent zone during that period when partially digested sludge was not emerging from the opening of said one of said pipes.

Claim 3

The improvement of claim 1 wherein said digestion tank is a generally circular tank and the openings of said plurality of pipes are spaced circumferentially about the base of said tank.

Claim 4

The improvement of claim 2 wherein at least one of said pipes has a portion immediately upstream of its effluent opening extending circumferentially about said tank.

Claim 5

The improvement of claim 1 including a discharge pipe extending from said tank for discharging partially digested sludge from said tank, a valve for closing said discharge pipe, said pump means communicating between said discharge pipe and said valve means.

Claim 6

In a sludge digestion facility of the type in which a body of sludge contained within a tank is digested in said tank by anaerobic bacteria, said body comprising a plurality of quiescent zones near the bottom of said tank, said tank having a discharge port through which partially digested sludge is periodically discharged to make room for incoming new sludge, the improvements including pipes mounted within said tank and having plural effluent openings adjacent the floor of said tank, each of said openings, opening into a respective one of said quiescent zones, a manifold having plural outlet ports each connecting separately to one of said pipes, pump means having communication between said manifold and said discharge port for forcing sludge being discharged from said tank through said manifold, sequential fluid switch means, valve means responsive to said switch means for sequentially distributing sludge forced to said manifold by said pump means through a single one of said outlet ports, into its respective quiescent zone, for a period sufficient to enable sludge emerging from said single one of said ports to substantially entirely displace materials which have settled in said respective quiescent zone during that period when sludge was not emerging from said single one of said ports, each of said effluent openings submerged below the level of sludge residing in said tank.

Claim 7

In a sludge digestion facility of the type in which a body of sludge contained within a tank is digested in said tank by anaerobic bacteria, said body comprising a plurality of quiescent zones near the bottom of said tank, said tank having a discharge port through which partially digested sludge is periodically discharged to make room for incoming new sludge, the improvements including pipes mounted within said tank and having plural effluent openings adjacent the floor of said tank, each of said openings, opening into a respective one of said quiescent zones, a manifold having plural outlet ports each connecting separately to one of said pipes, pump means having communication between said manifold and said discharge port for forcing sludge being discharged from said tank through said manifold, sequential fluid switch means, valve means responsive to said switch means for sequentially distributing sludge forced to said manifold by said pump means through a single one of said outlet ports, into its respective quiescent zone, for a period sufficient to enable sludge emerging from said single one of said ports to substantially entirely displace materials which have settled in said respective quiescent zone during that period when sludge was not emerging from said single one of said ports, each of said effluent openings submerged below the level of sludge residing in said tank.