Fixed bed reactor for carbon nanotube production

The utility model discloses a fixed bed reactor for carbon nanotube production, which comprises a quartz tube, an upper sealing plug is arranged at one end of the quartz tube, a lower sealing plug is arranged at the other end of the quartz tube, the sealing plugs are made of polytetrafluoroethylene, and a support frame is arranged at one end of the quartz tube close to the upper sealing plug. The pipe body is further provided with an extension section with a certain length outside the heating area, and the extension section is used for providing enough temperature drop gradient space and preventing the polytetrafluoroethylene sealing plug from being damaged. An air inlet pipe is arranged at the lower sealing plug, an air outlet pipe and a blind pipe are arranged at the upper sealing plug, the blind pipe is used for inserting a thermocouple, and a sand core plate bed layer is arranged in the quartz pipe. In the reaction process, reaction gas enters from the bottom and passes through the reactor from bottom to