Axial flow type, the general material spirals up along the wall of the container, and then converges to the central cavity to form an upper and lower convection cycle. At the same time, it has a strong anti-adhesion effect. It is suitable for mixing, heat transfer, reaction and dissolution operations of high viscosity or powdery materials. The form and number of ribbons should be determined according to the geometry of the container and the height of the liquid layer.