An apparatus for discharging bulk material from a storage tank includes a support shaft; an impeller wheel mounted on the support shaft in the vicinity of the storage tank floor; and a stepping mechanism for intermittently moving the impeller wheel in either direction. The stepping mechanism has a ratchet...http://www.google.es/patents/US4083462?utm_source=gb-gplus-sharePatente US4083462 - Apparatus for discharging bulk material from storage tanks
Apparatus for discharging bulk material from storage tanks
