摘要 |
A two-stage pumping apparatus is provided with a pump housing through which gross movement of material occurs generally from an infeed opening to a discharge opening. A first stage non-positive displacement helical flight auger is provided in a first stage region above, and coaxial with, one of a pair of second stage augers each having a positive displacement helical flight for engaging the material and for being respectively intermeshed to provide positive displacement pumping. |