Method for automatically circularly spraying and cleaning large reactor

The invention provides a method for automatically circularly spraying and cleaning a large reactor. The method comprises the following steps of conveying cleaning liquid by using a circulating pump, ensuring that the cleaning liquid enters a sealed impeller bin in the side direction, pushing an impeller in the sealed impeller bin to rotate by using flowing thrust of the cleaning liquid conveyed by the circulating pump so as to drive a lower water bin and a water distribution pipe which are connected through a bearing to rotate, ensuring that the cleaning liquid enters the water distribution pipe from the lower water bin, flows out of uniformly distributed nozzles on the lower part of the water distribution pipe and flows into a tube nest of the large shell and tube reactor to be cleaned below along with the rotation of the water distribution pipe, and ensuring that the cleaning liquid flowing out of the large shell and tube reactor flows into a collecting tank and enters the impeller bin through a water pump to push the impeller to rotate, thus recycling the cleaning liquid.