The invention provides for a seal assembly for a grain separator. A circuit portion 12 provides power supply voltage V10 to a node N0 through a first route 52 and power supply voltage V\u22125 to the node N0 through a second route 62. The high shear device may allow for lower reaction temperatures and pressures and may also reduce reaction time. The controller receives the direct range measurement and angle measurement from the sensor, and determines if the object is in an in-path area based upon the direct range measurement and angle measurement, as a function in a pseudo polar coordinate frame. The light sludge phase is fed as surplus sludge to a sludge digestion.