Patent ID: 7891964

Claim:
A pump system comprising: a first drive motor and a second drive motor; a delivery assembly operably engaged with the first drive motor and configured to feed a solid material under operational power of the first drive motor; and a screw pump comprising: a housing that at least partially defines a barrel of the screw pump; an extrusion tip secured to the housing at a first end of the barrel; a liquefier secured to the housing and intersecting with the barrel, the liquefier being configured to receive the solid material fed from the delivery assembly, to at least partially melt the received solid material, and to direct the at least partially melted material to the barrel, wherein the liquefier comprises a spiral baffle; and an impeller extending at least partially through the barrel, and configured to drive the at least partially melted material that is directed to the barrel toward the extrusion tip under operational power of the second drive motor.