Improved horizontal alkylation reactor

The invention relates to an improved horizontal alkylation reactor. The alkylation reactor includes a body. The body is internally provided with an internal circulation sleeve, and the back end is provided with a guide disc. The internal circulation sleeve is internally provided with a U-shaped tube heat exchange tube bundle; the guide disc is connected to a motor; a propeller is disposed between the tail end of the internal circulation sleeve and the guide disc, and the main shaft of the propeller is provided with a sealing system and is in direct connection with the motor. The sealing system adopts double end face dry gas seal, and is connected to the propeller main shaft through a shaft sleeve assembly. The shaft sleeve assembly is equipped with a spring seat and a gland respectively. Two sides of the spring seat are provided with a press sing, a moving ring and a stationary ring respectively. The gland is internally provided with a nitrogen or instrument air inelt, a leakage air outlet and a flushing port