Radial compressor

A radial compressor, comprising:

• a compressor rotor;
• a compressor housing, which has a radially outer spiral housing section and a radially inner insert section;
• a main flow channel configured to supply a medium to be compressed towards the compressor rotor;
• a circulation chamber arranged radially outside of the main flow channel;
• a contour wall that separates the circulation chamber from the main flow channel and is connected with the main flow channel via circulation, and which is connected with the radially inner insert section via struts extending into the circulation chamber,
• wherein the main flow channel is bordered by the contour wall, and upstream from the contour wall by an upstream portion of the radially inner insert section;
• and
• a suction element arranged upstream from the compressor housing, whose radially outer portion adjoins the spiral housing section, and whose radially inner portion adjoins the upstream portion of the radially inner insert section;
• wherein adjoining surfaces of the radially inner portion of the suction element and the upstream portion of the radially inner insert section lie on a cylindrical surface.