US Patent 7998728 Multiple tray vermicomposter with thermal siphon airflow

Multiple Tray Vermicomposter with Thermal Siphon Airflow is a vermiculture composting device that uses earthworms to create compost where worms eat and digest food to excrete compost. It is a multiple tray system with a base and a lid. New compost trays with freshly loaded food and bedding are stacked on top of older trays containing worms and compost to instigate a continuous upward migration of the worms thereby creating continuous compost production. Compost trays have permeable bottoms to allow worms to pass through. Compost production is accelerated from thermal siphon airflow to provide ample airflow to the worms without the requirement of a power source. Light-tight air-permeable connections between trays, lid, and base, also accelerate compost production by keeping the worms completely dark. If worms fall through the bottom compost tray, there exists a ramp to enable the fallen worms to climb back into the bottom compost tray.