Impinging stream reactor for preparing dichlorobutene by gas phase chlorination of butadiene

The invention provides an impinging stream reactor for preparing dichlorobutene by gas phase chlorination of butadiene. The impinging stream reactor comprises a reactor in a high-temperature state and a premixer in a normal-temperature state. A reaction gas inlet is formed in the side surface of the upper end part of the reactor, a reaction gas outlet is formed in the bottom end of the reactor, the upper end part in the reactor is an entrainment area, and the lower end part is a pipe flow area; the premixer comprises a main pipe and a side pipe arranged at the side end of the main pipe along the main pipe axis; two ends of the main pipe are respectively used as an ethylene feed port and a mixed gas discharge port, a plurality of rows of staggered first small holes and second small holes are formed in the overlapped part of the side surface and the side pipe, a certain angle is formed between the axis of the first small holes and the main pipe, and the second small holes are vertical to the main pipe; and the