The present invention is an air separation tube for an agricultural planter. The air separation tube comprises a hollow tube having an inlet and outlet that is mounted to the side wall of a mini-hopper. The tube is provided with a downwardly curving bend having a screen through which air is allowed to...http://www.google.com/patents/US5392722?utm_source=gb-gplus-sharePatent US5392722 - Air separation tube for a pneumatic delivery system
