Double drum systems and processes for converting biosolids to fertilizer

A system for converting biosolids to fertilizer comprising:

• a. a storage tank for holding biosolids,
• b. a conveyor and a pressurized screen, wherein the conveyor is operably connected to the storage tank and to the pressurized screen, wherein the conveyor transports the biosolids from the storage tank to the pressurized screen, wherein the pressurized screen selectively eliminates debris from the biosolids,
• c. a second conveyor and a centrifuge, wherein the second conveyor is operably connected to the pressurized screen to convey the biosolids to the centrifuge, wherein the centrifuge removes water from the biosolids,
• d. a third conveyor, a feeding chamber, a self-leveling conveyor, a nip feeder, a nip, and first and second dryer drums, wherein the third conveyor is operably connected to the centrifuge to convey the biosolids to the feeding chamber, the self-leveling conveyer is positioned in the feeding chamber, wherein the self-leveling conveyor delivers the biosolids to the nip feeder operatively positioned in the feeding chamber, wherein the nip feeder comprises a main bar that is activated to selectively move away from and toward the nip so that biosolids move from the feeding chamber to the nip, wherein the nip is a gap between the first and second dryer drums,
• e. the first and second dryer drums operatively positioned to rotate and draw biosolids from the nip feeder into the nip, wherein a first scraper is operably positioned to remove biosolids from the first dryer drum and a second scraper is operably positioned to remove biosolids from the second dryer drum as the first and second dryer drums rotate, and a boiler that provides steam to selectively heat the first and second dryer drums,
• f. a fourth conveyor and a pelletizer, wherein a portion of the fourth conveyor is positioned underneath the first and second dryer drums to collect the biosolids after they pass through the nip and the fourth conveyor transports the biosolids to the pelletizer, wherein the pelletizer forms the biosolids into pellets,
• g. a fifth conveyor and a cooling chamber, wherein the fifth conveyor is operably connected to the pelletizer to convey the pellets to the cooling chamber.