Container oxygen control system for transporting and ripening perishable

Abstract

A container oxygen control system includes multiple containers to hold perishable goods in a controlled ripening atmosphere composed primarily of nitrogen and oxygen. A first atmosphere control system controls the container atmosphere during the first transportation leg, such as from the place of harvest to a distribution port. The first atmosphere control system has a centralized nitrogen generator and multiple oxygen controllers which are provided for corresponding containers. The nitrogen generator generates a nitrogen enriched stream which is supplied to each oxygen controller. Each oxygen controller has an oxygen sensor to determine the oxygen content of the ripening atmosphere within the container. If the oxygen content remains above a preset threshold level, the oxygen controller injects the nitrogen enriched stream into the container at a constant rate to purge the container in a continuous manner. The container has an exhaust port to exhaust part of the ripening atmosphere from the container. If the oxygen content falls below the threshold level, however, the oxygen controller turns on a mixer to mix the nitrogen enriched stream with ambient air. This mixture is injected into the container to increase the oxygen content of the controlled ripening atmosphere. A second atmosphere control system controls the ripening atmosphere of the containers during a second transportation leg, such as from the port to the stores. The second atmosphere control system has multiple portable oxygen infusion units which mount directly to corresponding containers. The oxygen infusion units sense the oxygen content of the ripening atmosphere within the container, and selectively inject ambient air into the container to increase the oxygen content when it falls below a threshold level.