Cage-rotatable type marine riser vortex-induced vibration abatement device

The utility mode relates to a cage-rotatable type marine riser vortex-induced vibration abatement device. The cage-rotatable type marine riser vortex-induced vibration abatement device is composed of an upper rotation assembly, a lower rotation assembly and six blades, wherein the upper rotation assembly and the lower rotation assembly are symmetrical. Each rotation assembly is composed of an inner ring and an outer ring, wherein the inner ring and the outer ring are meshed, and the corresponding six blades are inserted into insertion holes of the outer ring through cylindrical bolts at the two ends to be fixed between the upper rotation assembly and the lower rotation assembly. After the blades are impacted by water flow, the rotation assemblies can be driven to rotate around a vertical pipe, the development of flow boundary layers and vortexes on the periphery of the vertical pipe is damaged, and vortex-induced vibration abatement is accordingly achieved. The blades are made of plastic, cost is low, the per