Apparatus for rapid machine composting of sewage sludge

Claim 1

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a plurality of radially extending carrier elements disposed around the inner face of said drum for moving composted sludge in the direction of rotation of said drum, a guide plate disposed adjacent the top of said drum and spaced from the inner surface thereof and cooperating with said carrier elements to catch the moving composted sludge, and a conveyor belt positioned inside said drum and extending longitudinally in the upper section of said drum interior above the level of the sludge compost and below said guide plate, said conveyor belt adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat, and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 2

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a plurality of radially extending carrier elements disposed around the inner face of said drum for moving composted sludge in the direction of rotation of said drum, a guide plate disposed adjacent the top of said drum and spaced from the inner surface thereof and cooperating with said carrier elements to catch the moving composted sludge, and a conveyor belt positioned inside said drum and extending longitudinally in the upper section of said drum interior above the level of the sludge compost and below said guide plate, said conveyor belt adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat, and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 5

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a substantially semi-circular drainage channel encompassing slightly more than the lower half of said drum, said channel being open on its side facing said drum and having an opening at its lower end, said drum having a plurality of spaced openings through its circumferential wall and aligned with said drainage channel, said openings permitting composted sludge to flow out of said drum into said channel, and a belt conveyor aligned with said channel opening and adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 6

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a substantially semi-circular drainage channel encompassing slightly more than the lower half of said drum, said channel being open on its side facing said drum and having an opening at its lower end, said drum having a plurality of spaced openings through its circumferential wall and aligned with said drainage channel, said openings permitting composted sludge to flow out of said drum into said channel, and a belt conveyor aligned with said channel opening and adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 8

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a worm conveyor extending into said drum and adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat, and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 9

An apparatus for the rapid machine composting of sewage sludge including a composting drum rotatable about a substantially horizontal axis and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessel; (b) means for feeding composted sludge from said drum back to said mixing vessel including a worm conveyor extending into said drum and adapted to deliver composted sludge to said mixing vessel; (c) a variable length conveyor adapted to receive sludge from said mixing vessel and extending longitudinally into the interior of said drum above the level of the sludge compost and operable to continuously feed sludge from said mixing vessel into said drum; (d) means for supplying and discharging air, heat, and moisture to and from the sludge compost inside said drum; and (e) means independent of said feeding means for continuously discharging composted material from said drum.

Claim 10

An apparatus for the rapid machine composting of sewage sludge including a rotary composting drum and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessels; (b) means in said drum forming a main composting zone, a drying zone, and a purification zone; (c) means extending longitudinally into the interior of said drum above the level of sludge compost for continuously feeding the resulting mixture from the mixing vessel into said drum, said continuous feeding means being operable to feed the sludge mixture to selected zones in said drum; (d) means of supplying and discharging air, heat and moisture to and from the sludge compost inside said drum; (e) means for continuously feeding composted sludge from said drum back into said mixing vessel, said continuous feed means being operable to remove composted sludge from said main composting zone and from said drying zone, or from selected areas thereof; and (f) means independent of said continuous feed means for continuously discharging composted material from said drum.

Claim 11

An apparatus for the rapid machine composting of sewage sludge including a rotary composting drum and comprising: (a) premixing means located outside said drum and including a mixing vessel, means for continuously delivering material to be composted to said mixing vessels; (b) means in said drum forming a main composting zone, a drying zone, and a purification zone; (c) means extending longitudinally into the interior of said drum above the level of sludge compost for continuously feeding the resulting mixture from the mixing vessel into said drum, said continuous feeding means being operable to feed the sludge mixture to selected zones in said drum; (d) means of supplying and discharging air, heat and moisture to and from the sludge compost inside said drum; (e) means for continuously feeding composted sludge from said drum back into said mixing vessel, said continuous feed means being operable to remove composted sludge from said main composting zone and from said drying zone, or from selected areas thereof; and (f) means independent of said continuous feed means for continuously discharging composted material from said drum.