The material and conveying medium are separated due to the fact that the gravitational force on the particles to be separated is greater than the energy of the carrier medium. With RSP suction excavators, this takes place by slowing down the air in the collecting tank and by diverting the flow direction. Due to their inertia, the particles are unable to follow and therefore drop out. This physical effect is utilized in the rear-mounted separation chamber of RSP suction excavators.