TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The ratio of the total volume of the tubular bodies to be filled with catalyst of the air-cooled reaction portion to the total volume of the tubular bodies to be filled with catalyst of the water-cooled reaction portion is (1-5):1. The reactor is a closed cylindrical container with a product outlet on one end face. The water-cooled reaction portion is arranged close to the product outlet end. At least one pair of cooling water outlet and inlet is arranged on the outer side surface of the water-cooled reaction portion. A number of catalyst tubes are arranged in the water-cooled reaction portion. An upper tube plate and a lower tube plate are arranged on the upper ends and lower ends of the catalyst tubes respectively. The same number of round holes as the catalyst tubes is formed on both the upper tube plate and the lower tube plate, and the area of each round hole is equal to the area of cross section of each catalyst tube. An inert magnetic ball and a catalyst contact agent support are disposed below the lower tube plate. The air-cooled reaction portion is arranged on the other end of the product outlet. At least one reactant inlet is formed on the outer side surface of the air-cooled reaction portion. A number of catalyst tubes are arranged in the air-cooled reaction portion. An inert magnetic ball is disposed on the end of each catalyst tube close to the water-cooled reaction portion. The air cooled shock portion connects the water-cooled reaction portion with the air-cooled reaction portion. At least one cold shock gas inlet is formed on the outer side surface of the air cooled shock portion, and a gas mixer is arranged in the air cooled shock portion. The gas mixer is a sieving plate with a number of spiral holes. The cylindrical container has a diameter of 2-6 m. 300-7000 catalyst tubes are provided. The inside diameter of the catalyst tubes is 22-58 mm, and the height of the catalyst tubes is 4-10 m. Each catalyst tube has an inside diameter of 22-58 mm and a height of 4-10 m. The gas mixer is a sieving plate with 2000-6000 spiral holes having a diameter of 2-5 mm.