A cone-stack centrifuge for separating particulate matter out of a circulating liquid includes a cone-stack assembly which is configured with a hollow rotor hub and is constructed to rotate about an axis. The cone-stack assembly is mounted onto a shaft centertube which is attached to a hollow base hub of a base assembly. The base assembly further includes a liquid inlet, a first passageway, and a second passageway which is connected to the first passageway. The liquid inlet is connected to the hollow base hub by the first passageway. A bearing arrangement is positioned between the rotor hub and the shaft centertube for rotary motion of the cone-stack assembly. An impulse-turbine wheel is attached to the rotor hub and a flow jet nozzle is positioned so as to be directed at the turbine wheel. The flow jet nozzle is coupled to the second passageway for directing a flow jet of liquid at the turbine wheel in order to impart rotary motion to the cone-stack assembly. The liquid for the flow jet nozzle enters the cone-stack centrifuge by way of the liquid inlet. The same liquid inlet also provides the liquid which is circulated through the cone-stack assembly. A honeycomb-like insert is assembled into the flow jet nozzle in order to reduce inlet turbulence and improve the turbine efficiency.