A radial turbomachine includes a radial diffuser channel with a diaphragm, a deflecting channel connecting to the radial diffuser channel downstream thereof, and a return flow channel connecting to the deflecting channel downstream thereof. The main flow direction of the radial diffuser channel runs radially from inside to outside. The main flow direction of the deflecting channel is deflected from radially outward to radially inward. The main flow direction of the return channel runs radially from outside to inside. The diaphragm comprises first, second and third outer surface sections. The first outer surface section has a convex shape for delimiting the deflecting channel. At least one consumption-gas removal channel is provided in the diaphragm so that, if the main flow in the deflecting channel comprises solid or liquid particles, a consumption gas can be discharged therefrom through the consumption-gas removal channel as low-particulate gas of a main flow.