2.1.1. Separating egg shells from hatchery waste
A powerful suction vacuum is used to only remove the dry, very light shells from the hatchery waste, leaving the heavier infertile eggs (World Intellectual Property Organization-WO/2001/074491, Eggshell waste processing method and device). The shell and non-shell materials can also be separated by using a vibrating or shaking device (e.g., a shaker-sieve belt), which can separate lighter parts from heavier parts in the hatchery waste. A stream of gas (such as a cyclone forced-air separator) also can be used to separate lighter materials from heavier materials in hatchery waste. After hatching, live chicks and unhatched chicks or clear eggs from the hatching tray are placed on a moving belt with fixed gaps that only allow chicks to slide through, while shells and unhatched eggs are retained on the belt. Then the shell is vacuumed up for further separation, with the dead embryos being disposed into a separate container (World Intellectual Property Organization-WO/2001/074491, Eggshell waste processing method and device).